diff --git a/app/src/main/java/org/greenstand/android/TreeTracker/profile/ProfileScreen.kt b/app/src/main/java/org/greenstand/android/TreeTracker/profile/ProfileScreen.kt
index 41e94b9e..d5d2e750 100644
--- a/app/src/main/java/org/greenstand/android/TreeTracker/profile/ProfileScreen.kt
+++ b/app/src/main/java/org/greenstand/android/TreeTracker/profile/ProfileScreen.kt
@@ -59,6 +59,12 @@ import org.greenstand.android.TreeTracker.view.LocalImage
 import org.greenstand.android.TreeTracker.view.ProfileField
 import org.greenstand.android.TreeTracker.view.TreeTrackerButton
 import java.io.File
+import org.greenstand.android.TreeTracker.utils.ValidationUtils
+import androidx.compose.material.MaterialTheme
+import androidx.compose.runtime.mutableStateOf
+import androidx.compose.runtime.remember
+import androidx.compose.runtime.setValue
+import androidx.compose.runtime.getValue
 
 @Composable
 fun ProfileScreen(
@@ -79,6 +85,21 @@ fun ProfileScreen(
             }
         }
     }
+    var firstNameError by remember { mutableStateOf<String?>(null) }
+    var lastNameError by remember { mutableStateOf<String?>(null) }
+
+    fun validateNames(): Boolean {
+        val firstName = state.selectedUser?.firstName ?: ""
+        val lastName = state.selectedUser?.lastName ?: ""
+
+        val (firstNameValid, firstError) = ValidationUtils.validateName(firstName)
+        val (lastNameValid, lastError) = ValidationUtils.validateName(lastName)
+
+        firstNameError = firstError
+        lastNameError = lastError
+
+        return firstNameValid && lastNameValid
+    }
     Scaffold(
         topBar = {
             ActionBar(
@@ -155,11 +176,45 @@ fun ProfileScreen(
                 Spacer(modifier = Modifier.height(16.dp))
 
                 ProfileField(stringResource(id = R.string.first_name_hint), selectedUser.firstName, state.editMode) {
-                    viewModel.updateSelectedUser(firstName = it)
+                    newFirstName ->
+
+                    val filtered = ValidationUtils.filterNameInput(newFirstName)
+                    viewModel.updateSelectedUser(firstName = filtered)
+                    if (state.editMode) {
+                        val (_, error) = ValidationUtils.validateName(filtered)
+                        firstNameError = error
+                    }
+                }
+
+                if (state.editMode && firstNameError != null) {
+                    Text(
+                        text = firstNameError!!,
+                        color = MaterialTheme.colors.error,
+                        style = CustomTheme.typography.small,
+                        modifier = Modifier.padding(start = 8.dp, top = 4.dp)
+                    )
                 }
+                Spacer(modifier = Modifier.height(8.dp))
 
-                ProfileField(stringResource(id = R.string.last_name_hint), selectedUser.lastName ?: "", state.editMode) {
-                    viewModel.updateSelectedUser(lastName = it)
+                ProfileField(
+                    stringResource(id = R.string.last_name_hint), selectedUser.lastName ?: "", state.editMode) {
+                    newLastName ->
+                    val filtered = ValidationUtils.filterNameInput(newLastName)
+                    viewModel.updateSelectedUser(lastName = filtered)
+
+                    if (state.editMode) {
+                        val (_, error) = ValidationUtils.validateName(filtered)
+                        lastNameError = error
+                    }
+                }
+
+                if (state.editMode && lastNameError != null) {
+                    Text(
+                        text = lastNameError!!,
+                        color = MaterialTheme.colors.error,
+                        style = CustomTheme.typography.small,
+                        modifier = Modifier.padding(start = 8.dp, top = 4.dp)
+                    )
                 }
                 if (selectedUser.wallet.contains("@")) {
                     ProfileField(stringResource(id = R.string.email_placeholder), selectedUser.wallet ?: "", state.editMode) {
@@ -180,10 +235,16 @@ fun ProfileScreen(
                             .align(Alignment.CenterHorizontally)
                             .size(width = 150.dp, 60.dp),
                         onClick = {
+                            // 验证名字
+                            val firstName = state.selectedUser?.firstName ?: ""
+                            val lastName = state.selectedUser?.lastName ?: ""
 
-                            scope.launch {
-                                viewModel.updateUserInDatabase()
-                                viewModel.updateEditEnabled()
+                            if (ValidationUtils.validateName(firstName).first &&
+                                ValidationUtils.validateName(lastName).first) {
+                                scope.launch {
+                                    viewModel.updateUserInDatabase()
+                                    viewModel.updateEditEnabled()
+                                }
                             }
                         }
                     ) {
diff --git a/app/src/main/java/org/greenstand/android/TreeTracker/signup/NameEntryView.kt b/app/src/main/java/org/greenstand/android/TreeTracker/signup/NameEntryView.kt
index 110d7b34..0b2a3d8a 100644
--- a/app/src/main/java/org/greenstand/android/TreeTracker/signup/NameEntryView.kt
+++ b/app/src/main/java/org/greenstand/android/TreeTracker/signup/NameEntryView.kt
@@ -49,6 +49,13 @@ import org.greenstand.android.TreeTracker.view.ArrowButton
 import org.greenstand.android.TreeTracker.view.BorderedTextField
 import org.greenstand.android.TreeTracker.view.LanguageButton
 import org.greenstand.android.TreeTracker.view.TopBarTitle
+import org.greenstand.android.TreeTracker.utils.ValidationUtils
+import androidx.compose.material.MaterialTheme
+import androidx.compose.material.Text
+import androidx.compose.foundation.layout.padding
+import androidx.compose.ui.unit.dp
+import androidx.compose.foundation.layout.Spacer
+import androidx.compose.foundation.layout.height
 
 @Composable
 fun NameEntryView(viewModel: SignupViewModel, state: SignUpState) {
@@ -95,8 +102,7 @@ fun NameEntryView(viewModel: SignupViewModel, state: SignUpState) {
                 rightAction = {
                     ArrowButton(
                         isLeft = false,
-                        isEnabled = !state.firstName.isNullOrBlank() &&
-                            !state.lastName.isNullOrBlank()
+                        isEnabled = viewModel.isFormValid()
                     ) {
                         cameraLauncher.launch(true)
                     }
@@ -128,6 +134,15 @@ fun NameEntryView(viewModel: SignupViewModel, state: SignUpState) {
                     }
                 )
             )
+            state.firstNameError?.let { error ->
+                Text(
+                    text = error,
+                    color = MaterialTheme.colors.error,
+                    style = MaterialTheme.typography.caption,
+                    modifier = Modifier.padding(start = 8.dp, top = 4.dp)
+                )
+            }
+            Spacer(modifier = Modifier.height(8.dp))
             BorderedTextField(
                 value = state.lastName ?: "",
                 padding = PaddingValues(4.dp),
@@ -146,6 +161,14 @@ fun NameEntryView(viewModel: SignupViewModel, state: SignUpState) {
                     }
                 )
             )
+            state.lastNameError?.let { error ->
+                Text(
+                    text = error,
+                    color = MaterialTheme.colors.error,
+                    style = MaterialTheme.typography.caption,
+                    modifier = Modifier.padding(start = 8.dp, top = 4.dp)
+                )
+            }
         }
     }
 }
\ No newline at end of file
diff --git a/app/src/main/java/org/greenstand/android/TreeTracker/signup/SignupViewModel.kt b/app/src/main/java/org/greenstand/android/TreeTracker/signup/SignupViewModel.kt
index 09d4785f..4255976a 100644
--- a/app/src/main/java/org/greenstand/android/TreeTracker/signup/SignupViewModel.kt
+++ b/app/src/main/java/org/greenstand/android/TreeTracker/signup/SignupViewModel.kt
@@ -25,6 +25,7 @@ import org.greenstand.android.TreeTracker.models.UserRepo
 import org.greenstand.android.TreeTracker.models.user.User
 import org.greenstand.android.TreeTracker.usecases.CheckForInternetUseCase
 import org.greenstand.android.TreeTracker.utilities.Validation
+import org.greenstand.android.TreeTracker.utils.ValidationUtils
 
 // Dequeue breaks equals so state will not be updated when navigating
 data class SignUpState(
@@ -43,6 +44,8 @@ data class SignUpState(
     val isTherePowerUser: Boolean? = null,
     val showSelfieTutorial: Boolean? = null,
     val showPrivacyDialog: Boolean? = true,
+    val firstNameError: String? = null,
+    val lastNameError: String? = null,
 )
 
 sealed class Credential {
@@ -90,11 +93,27 @@ class SignupViewModel(
     }
 
     fun updateFirstName(firstName: String?) {
-        _state.value = _state.value?.copy(firstName = firstName)
+        val filtered = firstName?.let { ValidationUtils.filterNameInput(it) }
+        val (isValid, error) = ValidationUtils.validateName(filtered)
+        _state.value = _state.value?.copy(
+            firstName = filtered,
+            firstNameError = if (filtered.isNullOrEmpty()) null else error
+        )
     }
 
     fun updateLastName(lastName: String?) {
-        _state.value = _state.value?.copy(lastName = lastName)
+        val filtered = lastName?.let { ValidationUtils.filterNameInput(it) }
+        val (isValid, error) = ValidationUtils.validateName(filtered)
+        _state.value = _state.value?.copy(
+            lastName = filtered,
+            lastNameError = if (filtered.isNullOrEmpty()) null else error
+        )
+    }
+    fun isFormValid(): Boolean {
+        val state = _state.value ?: return false
+        val (firstNameValid, _) = ValidationUtils.validateName(state.firstName)
+        val (lastNameValid, _) = ValidationUtils.validateName(state.lastName)
+        return firstNameValid && lastNameValid
     }
 
     fun setExistingUserAsPowerUser(id: Long){
diff --git a/app/src/main/java/org/greenstand/android/TreeTracker/utils/ValidationUtils.kt b/app/src/main/java/org/greenstand/android/TreeTracker/utils/ValidationUtils.kt
new file mode 100644
index 00000000..9420f2bd
--- /dev/null
+++ b/app/src/main/java/org/greenstand/android/TreeTracker/utils/ValidationUtils.kt
@@ -0,0 +1,48 @@
+package org.greenstand.android.TreeTracker.utils
+
+/**
+ * Utility class for validating user input fields
+ */
+object ValidationUtils {
+
+    private val NAME_PATTERN = """^[\p{L}\s'-]+$""".toRegex()
+
+    private val INVALID_CHARS_PATTERN = """[0-9!@#$%^&*()_+=\[\]{};:"|<>?,./\\~`]""".toRegex()
+
+    /**
+     * Validates a name field (first name or last name)
+     * @param name The name to validate
+     * @return Pair of (isValid, errorMessage)
+     */
+    fun validateName(name: String?): Pair<Boolean, String?> {
+        return when {
+            name.isNullOrBlank() -> {
+                false to "Name cannot be empty"
+            }
+            name.trim().length < 2 -> {
+                false to "Name must be at least 2 characters"
+            }
+            name.length > 50 -> {
+                false to "Name cannot exceed 50 characters"
+            }
+            INVALID_CHARS_PATTERN.containsMatchIn(name) -> {
+                false to "Name cannot contain numbers or special characters"
+            }
+            !NAME_PATTERN.matches(name.trim()) -> {
+                false to "Name can only contain letters, spaces, hyphens and apostrophes"
+            }
+            else -> {
+                true to null
+            }
+        }
+    }
+
+    /**
+     * Filters out invalid characters from input
+     */
+    fun filterNameInput(input: String): String {
+        return input.filter { char ->
+            char.isLetter() || char.isWhitespace() || char == '-' || char == '\''
+        }.take(50) // Also enforce max length
+    }
+}
\ No newline at end of file
diff --git a/app/src/main/res/values/strings.xml b/app/src/main/res/values/strings.xml
index 4e27e51a..e71efa9f 100644
--- a/app/src/main/res/values/strings.xml
+++ b/app/src/main/res/values/strings.xml
@@ -204,4 +204,10 @@ Privacy Policy
     <string name="survey_completed">Survey Completed</string>
     <string name="upload_trees_soon_title">Upload Trees Soon</string>
     <string name="upload_trees_text_content">You have over 2000 trees, please upload as soon as you can.</string>
+
+    <string name="error_name_empty">Name cannot be empty</string>
+    <string name="error_name_too_short">Name must be at least 2 characters</string>
+    <string name="error_name_too_long">Name cannot exceed 50 characters</string>
+    <string name="error_name_invalid">Name cannot contain numbers or special characters</string>
+    <string name="error_name_format">Name can only contain letters, spaces, hyphens and apostrophes</string>
 </resources>
diff --git a/app/src/test/java/org/greenstand/android/TreeTracker/utils/ValidationUtilsTest.kt b/app/src/test/java/org/greenstand/android/TreeTracker/utils/ValidationUtilsTest.kt
new file mode 100644
index 00000000..a6867dc1
--- /dev/null
+++ b/app/src/test/java/org/greenstand/android/TreeTracker/utils/ValidationUtilsTest.kt
@@ -0,0 +1,61 @@
+package org.greenstand.android.TreeTracker.utils
+
+import org.junit.Assert.*
+import org.junit.Test
+
+class ValidationUtilsTest {
+
+    @Test
+    fun `valid names should pass validation`() {
+        val validNames = listOf(
+            "John",
+            "Mary-Jane",
+            "O'Connor",
+            "José María",
+            "李明",
+            "François"
+        )
+
+        validNames.forEach { name ->
+            val (isValid, error) = ValidationUtils.validateName(name)
+            assertTrue("$name should be valid", isValid)
+            assertNull("$name should have no error", error)
+        }
+    }
+
+    @Test
+    fun `names with numbers should fail`() {
+        val invalidNames = listOf("John123", "4ever", "Test1")
+
+        invalidNames.forEach { name ->
+            val (isValid, error) = ValidationUtils.validateName(name)
+            assertFalse("$name should be invalid", isValid)
+            assertEquals("Name cannot contain numbers or special characters", error)
+        }
+    }
+
+    @Test
+    fun `names with special characters should fail`() {
+        val invalidNames = listOf("John@Doe", "Test!", "Name#1")
+
+        invalidNames.forEach { name ->
+            val (isValid, error) = ValidationUtils.validateName(name)
+            assertFalse("$name should be invalid", isValid)
+            assertNotNull(error)
+        }
+    }
+
+    @Test
+    fun `empty name should fail`() {
+        val (isValid, error) = ValidationUtils.validateName("")
+        assertFalse(isValid)
+        assertEquals("Name cannot be empty", error)
+    }
+
+    @Test
+    fun `filterNameInput removes invalid characters`() {
+        assertEquals("John", ValidationUtils.filterNameInput("John123"))
+        assertEquals("MaryJane", ValidationUtils.filterNameInput("Mary@Jane"))
+        assertEquals("Test", ValidationUtils.filterNameInput("Test!@#"))
+    }
+}
\ No newline at end of file