diff --git a/src/main/java/khu/bigdata/infou/business/LectureConverter.java b/src/main/java/khu/bigdata/infou/business/LectureConverter.java
index 55206b2..9200bab 100644
--- a/src/main/java/khu/bigdata/infou/business/LectureConverter.java
+++ b/src/main/java/khu/bigdata/infou/business/LectureConverter.java
@@ -86,8 +86,8 @@ public static LectureResponseDTO.LectureDetailDto toLectureDetailDto(LectureUdem
     public static LectureResponseDTO.OtherStudentsListInfo toOtherStudentInfo(PlatformStudent student) {
 
         return LectureResponseDTO.OtherStudentsListInfo.builder()
-                .inflearnUserId(Long.valueOf(student.getInflearnUserId()))
-                .udemyUserId(Long.valueOf(student.getUdemyUserId()))
+                .inflearnUserId(student.getInflearnUserId() != null ? student.getInflearnUserId() : null)
+                .udemyUserId(student.getUdemyUserId() != null ? student.getUdemyUserId() : null)
                 .name(student.getName())
                 .topword1(student.getTopword1())
                 .topword2(student.getTopword2())
diff --git a/src/main/java/khu/bigdata/infou/implement/LectureService.java b/src/main/java/khu/bigdata/infou/implement/LectureService.java
index d087aae..688da6e 100644
--- a/src/main/java/khu/bigdata/infou/implement/LectureService.java
+++ b/src/main/java/khu/bigdata/infou/implement/LectureService.java
@@ -2,6 +2,7 @@
 
 import khu.bigdata.infou.business.LectureConverter;
 import khu.bigdata.infou.domain.LectureDetail;
+import khu.bigdata.infou.domain.LectureInflearn;
 import khu.bigdata.infou.domain.LectureUdemy;
 import khu.bigdata.infou.domain.PlatformStudent;
 import khu.bigdata.infou.repository.LectureDetailRepository;
@@ -11,11 +12,8 @@
 import khu.bigdata.infou.web.dto.LectureResponseDTO;
 import lombok.RequiredArgsConstructor;
 import lombok.extern.slf4j.Slf4j;
-import org.springframework.data.domain.PageRequest;
-import org.springframework.data.domain.Pageable;
 import org.springframework.stereotype.Service;
 
-import java.util.ArrayList;
 import java.util.Comparator;
 import java.util.List;
 import java.util.stream.Collectors;
@@ -37,11 +35,37 @@ public class LectureService {
     public LectureResponseDTO.CategoryRecommendLectureDto findRecommendedLectureByCategory(String category) {
 
         if (category == null) {
-            // 카테고리 프로그래밍 언어로 고정해서 가져와라
+            // default category(udemy)
             category = "Programming Languages";
         }
+
+        //inflearn 강좌 조회 추가
+
+        // default category(inflearn)
+        String categoryInflearn = "프로그래밍 언어";
+
+        String firstCategory = null;
+        String secondCategory = null;
+
+        categoryInflearn = switch (category) {
+            case "Programming Languages" -> "프로그래밍 언어";
+            case "Web Development" -> "웹 개발";
+            case "Game Development" -> "게임 개발";
+            case "Mobile Development" -> "모바일 개발";
+            case "Data Science" -> "데이터 사이언스";
+            default -> categoryInflearn;
+        };
+
+        String[] parts = categoryInflearn.split(" ");
+        if (parts.length == 2) {
+            firstCategory = parts[0];
+            secondCategory = parts[1];
+        }
+
         List<LectureUdemy> lectureUdemyList = lectureUdemyRepository.findAllBySubcategory(category);
 
+        List<LectureInflearn> lectureInflearnList = lectureInflearnRepository.findAllByFirstCategoryAndSecondCategory(firstCategory, secondCategory);
+
         // 일단 가져오고 상위 값 추출
         List<LectureUdemy> sortedList = lectureUdemyList.stream()
                 .sorted(Comparator.comparingDouble((LectureUdemy lecture) -> lecture.getAvgRating() * lecture.getNumReviews()).reversed())
@@ -96,26 +120,12 @@ public LectureResponseDTO.LectureDetailDto findLectureDetail(Integer lectureId)
      */
     public LectureResponseDTO.OtherStudentsDto findOtherStudents() {
 
-        Pageable pageable = PageRequest.of(0, 1000);
-
-        // 쿼리 실행
-        List<Object[]> topStudents = platformStudentRepository.findTopStudents(pageable);
-
-        // 조회된 데이터를 List로 변환
-        List<PlatformStudent> studentList = new ArrayList<>();
-        for (Object[] result : topStudents) {
-            Integer userId = (Integer) result[0];
-            List<PlatformStudent> students;
-            if (userId != null) {
-                students = platformStudentRepository.findByInflearnUserId(userId);
-                if (students.isEmpty()) {
-                    students = platformStudentRepository.findByUdemyUserId(userId);
-                }
-            } else {
-                students = new ArrayList<>();
-            }
-            studentList.addAll(students);
-        }
+        List<PlatformStudent> platformStudents = platformStudentRepository.findAllWithUdemyUserId();
+
+        // 가져온 데이터를 List로 변환
+        List<PlatformStudent> studentList = platformStudents.stream()
+                .limit(1000) // 상위 1000개로 제한
+                .collect(Collectors.toList());
 
         return LectureConverter.toOtherStudentsDto(studentList);
     }
diff --git a/src/main/java/khu/bigdata/infou/repository/LectureInflearnRepository.java b/src/main/java/khu/bigdata/infou/repository/LectureInflearnRepository.java
index fd4353f..ba99333 100644
--- a/src/main/java/khu/bigdata/infou/repository/LectureInflearnRepository.java
+++ b/src/main/java/khu/bigdata/infou/repository/LectureInflearnRepository.java
@@ -3,9 +3,12 @@
 import khu.bigdata.infou.domain.LectureInflearn;
 import org.springframework.data.jpa.repository.JpaRepository;
 
+import java.util.List;
 import java.util.Optional;
 
 public interface LectureInflearnRepository extends JpaRepository<LectureInflearn, Long> {
 
     Optional<LectureInflearn> findByLectureId(Integer lectureId);
+
+    List<LectureInflearn> findAllByFirstCategoryAndSecondCategory(String firstCategory, String secondCategory);
 }
diff --git a/src/main/java/khu/bigdata/infou/repository/PlatformStudentRepository.java b/src/main/java/khu/bigdata/infou/repository/PlatformStudentRepository.java
index 392eef6..5999329 100644
--- a/src/main/java/khu/bigdata/infou/repository/PlatformStudentRepository.java
+++ b/src/main/java/khu/bigdata/infou/repository/PlatformStudentRepository.java
@@ -1,22 +1,13 @@
 package khu.bigdata.infou.repository;
 
 import khu.bigdata.infou.domain.PlatformStudent;
-import org.springframework.data.domain.Pageable;
 import org.springframework.data.jpa.repository.JpaRepository;
 import org.springframework.data.jpa.repository.Query;
 
 import java.util.List;
 
 public interface PlatformStudentRepository extends JpaRepository<PlatformStudent, Long> {
-
-    @Query("SELECT p.inflearnUserId AS userId, COUNT(p) AS cnt FROM PlatformStudent p WHERE p.inflearnUserId IS NOT NULL GROUP BY p.inflearnUserId " +
-            "UNION " +
-            "SELECT p.udemyUserId AS userId, COUNT(p) AS cnt FROM PlatformStudent p WHERE p.udemyUserId IS NOT NULL GROUP BY p.udemyUserId " +
-            "ORDER BY cnt DESC")
-    List<Object[]> findTopStudents(Pageable pageable);
-
-    List<PlatformStudent> findByInflearnUserId(Integer userId);
-
-    List<PlatformStudent> findByUdemyUserId(Integer userId);
+    @Query("SELECT p FROM PlatformStudent p WHERE p.udemyUserId IS NOT NULL")
+    List<PlatformStudent> findAllWithUdemyUserId();
 }
 
diff --git a/src/main/java/khu/bigdata/infou/web/dto/LectureResponseDTO.java b/src/main/java/khu/bigdata/infou/web/dto/LectureResponseDTO.java
index a5513e0..526f5cb 100644
--- a/src/main/java/khu/bigdata/infou/web/dto/LectureResponseDTO.java
+++ b/src/main/java/khu/bigdata/infou/web/dto/LectureResponseDTO.java
@@ -105,8 +105,8 @@ public static class LectureDetailDto {
     @AllArgsConstructor
     public static class OtherStudentsListInfo {
 
-        private Long inflearnUserId;
-        private Long udemyUserId;
+        private Integer inflearnUserId;
+        private Integer udemyUserId;
         private String name;
 
         private String topword1;