diff --git a/back-end/reacton/src/main/java/com/softeer/reacton/domain/course/ProfessorCourseService.java b/back-end/reacton/src/main/java/com/softeer/reacton/domain/course/ProfessorCourseService.java
index 40ff3ed..05c5557 100644
--- a/back-end/reacton/src/main/java/com/softeer/reacton/domain/course/ProfessorCourseService.java
+++ b/back-end/reacton/src/main/java/com/softeer/reacton/domain/course/ProfessorCourseService.java
@@ -159,6 +159,7 @@ public void startCourse(String oauthId, long courseId) {
 
         Course course = getCourseByProfessor(oauthId, courseId);
         course.activate();
+        questionRepository.deleteAllByCourse(course);
 
         log.info("수업이 시작 상태로 변경되었습니다. courseId = {}", courseId);
     }
@@ -169,6 +170,7 @@ public void closeCourse(String oauthId, long courseId) {
 
         Course course = getCourseByProfessor(oauthId, courseId);
         course.deactivate();
+        questionRepository.deleteCompleteByCourse(course);
 
         log.debug("SSE 서버에 수업 종료 메시지 전송을 요청합니다.");
         SseMessage<Void> sseMessage = new SseMessage<>("COURSE_CLOSED", null);
diff --git a/back-end/reacton/src/main/java/com/softeer/reacton/domain/question/QuestionRepository.java b/back-end/reacton/src/main/java/com/softeer/reacton/domain/question/QuestionRepository.java
index d89afbd..50ece14 100644
--- a/back-end/reacton/src/main/java/com/softeer/reacton/domain/question/QuestionRepository.java
+++ b/back-end/reacton/src/main/java/com/softeer/reacton/domain/question/QuestionRepository.java
@@ -10,7 +10,9 @@
 import java.util.List;
 
 public interface QuestionRepository extends JpaRepository<Question, Long> {
-    List<Question> findByStudentIdAndCourse(String studentId, Course course);
+    @Query("SELECT q FROM Question q " +
+            "WHERE q.studentId = :studentId AND q.course = :course AND q.isComplete = false")
+    List<Question> findNotCompleteByStudentIdAndCourse(String studentId, Course course);
 
     @Modifying
     @Transactional
@@ -18,5 +20,11 @@ public interface QuestionRepository extends JpaRepository<Question, Long> {
             "WHERE q.studentId = :studentId AND q.course = :course AND q.id = :questionId")
     int updateQuestion(@Param("studentId") String studentId, @Param("course") Course course, @Param("questionId") Long questionId);
 
+    @Modifying
+    @Transactional
+    @Query("DELETE FROM Question q " +
+            "WHERE q.course = :course AND q.isComplete = true")
+    void deleteCompleteByCourse(@Param("course") Course course);
+
     void deleteAllByCourse(Course course);
 }
diff --git a/back-end/reacton/src/main/java/com/softeer/reacton/domain/question/StudentQuestionService.java b/back-end/reacton/src/main/java/com/softeer/reacton/domain/question/StudentQuestionService.java
index ef4d302..7094048 100644
--- a/back-end/reacton/src/main/java/com/softeer/reacton/domain/question/StudentQuestionService.java
+++ b/back-end/reacton/src/main/java/com/softeer/reacton/domain/question/StudentQuestionService.java
@@ -33,7 +33,7 @@ public QuestionAllResponse getQuestionsByStudentId(String studentId, Long course
         log.debug("이전에 질문했던 목록을 조회합니다. : studentId = {}, courseId = {}", studentId, courseId);
 
         Course course = getCourse(courseId);
-        List<CourseQuestionResponse> questions = findQuestions(studentId, course);
+        List<CourseQuestionResponse> questions = findQuestionsNotComplete(studentId, course);
 
         return QuestionAllResponse.of(questions);
     }
@@ -95,8 +95,8 @@ private Course getCourse(Long courseId) {
                 .orElseThrow(() -> new BaseException(CourseErrorCode.COURSE_NOT_FOUND));
     }
 
-    private List<CourseQuestionResponse> findQuestions(String studentId, Course course) {
-        List<Question> questions =  questionRepository.findByStudentIdAndCourse(studentId, course);
+    private List<CourseQuestionResponse> findQuestionsNotComplete(String studentId, Course course) {
+        List<Question> questions =  questionRepository.findNotCompleteByStudentIdAndCourse(studentId, course);
 
         return questions.stream()
                 .map(question -> new CourseQuestionResponse(