diff --git a/src/InterviewAssistant.AppHost/InterviewAssistant.AppHost.csproj b/src/InterviewAssistant.AppHost/InterviewAssistant.AppHost.csproj
index af47e8b..fb6d720 100644
--- a/src/InterviewAssistant.AppHost/InterviewAssistant.AppHost.csproj
+++ b/src/InterviewAssistant.AppHost/InterviewAssistant.AppHost.csproj
@@ -1,6 +1,6 @@
 <Project Sdk="Microsoft.NET.Sdk">
 
-  <Sdk Name="Aspire.AppHost.Sdk" Version="9.3.0" />
+  <Sdk Name="Aspire.AppHost.Sdk" Version="9.4.0" />
 
   <PropertyGroup>
     <OutputType>Exe</OutputType>
diff --git a/src/InterviewAssistant.Web/Components/Pages/Home.razor b/src/InterviewAssistant.Web/Components/Pages/Home.razor
index 3f6b540..bc8e139 100644
--- a/src/InterviewAssistant.Web/Components/Pages/Home.razor
+++ b/src/InterviewAssistant.Web/Components/Pages/Home.razor
@@ -160,7 +160,7 @@
             StateHasChanged();
             
             var assistantMessage = new ChatMessage 
-            { 
+            {
                 Role = MessageRoleType.Assistant, 
                 Message = string.Empty 
             };
@@ -207,7 +207,8 @@
     // 키 입력 처리 (엔터키로 메시지 전송)
     private async Task HandleKeyDown(KeyboardEventArgs e)
     {
-        if (e.Repeat || isSend) return;
+        var isSendJs = await JSRuntime.InvokeAsync<bool>("isMessageSendInProgress");
+        if (e.Repeat || isSend || isSendJs) return;
         
         isSend = true;
         
@@ -273,7 +274,7 @@
 
             bool first = true;
             await foreach (var response in responses)
-            {    
+            {
                 if (first)
                 {
                     isLoading = false;
diff --git a/src/InterviewAssistant.Web/wwwroot/js/chatFunctions.js b/src/InterviewAssistant.Web/wwwroot/js/chatFunctions.js
index 653c880..c44d6fe 100644
--- a/src/InterviewAssistant.Web/wwwroot/js/chatFunctions.js
+++ b/src/InterviewAssistant.Web/wwwroot/js/chatFunctions.js
@@ -102,4 +102,8 @@ window.resetTextAreaHeight = function (elementId) {
         textarea.style.height = "";
         textarea.style.overflowY = "hidden";
     }
+};
+
+window.isMessageSendInProgress = function () {
+    return window.isSend || false;
 };
\ No newline at end of file
diff --git a/test/InterviewAssistant.AppHost.Tests/Components/Pages/HomeTests.cs b/test/InterviewAssistant.AppHost.Tests/Components/Pages/HomeTests.cs
index fcc799c..09493de 100644
--- a/test/InterviewAssistant.AppHost.Tests/Components/Pages/HomeTests.cs
+++ b/test/InterviewAssistant.AppHost.Tests/Components/Pages/HomeTests.cs
@@ -363,6 +363,18 @@ public async Task Home_HandleKeyDown_PreventsDuplicateWithIsSendFlag()
             Timeout = 5000
         });
 
+        // 초기 AI 응답 및 UI 준비 대기
+        await Page.WaitForSelectorAsync(".welcome-message", new PageWaitForSelectorOptions
+        {
+            State = WaitForSelectorState.Detached,
+            Timeout = 15000
+        });
+        await Page.WaitForSelectorAsync(".response-status", new PageWaitForSelectorOptions
+        {
+            State = WaitForSelectorState.Detached,
+            Timeout = 40000
+        });
+
         var textarea = Page.Locator("textarea#messageInput");
         
         // 초기 메시지 개수 확인