diff --git a/src/main/java/doit/apihw/api/controller/AuthController.java b/src/main/java/doit/apihw/api/controller/AuthController.java
index 918dd83..7dc39f9 100644
--- a/src/main/java/doit/apihw/api/controller/AuthController.java
+++ b/src/main/java/doit/apihw/api/controller/AuthController.java
@@ -28,6 +28,7 @@ public MemberController(MemberService memberService) {
      */
     @GetMapping("/auth/members/validate")
     public void validateLoginId(@RequestParam String memberLoginId) {
+
         authService.validateLoginId(memberLoginId);
     }
 
diff --git a/src/main/java/doit/apihw/api/controller/MemberController.java b/src/main/java/doit/apihw/api/controller/MemberController.java
index d1e5890..9312201 100644
--- a/src/main/java/doit/apihw/api/controller/MemberController.java
+++ b/src/main/java/doit/apihw/api/controller/MemberController.java
@@ -2,6 +2,7 @@
 
 import doit.apihw.api.controller.dto.AuthPasswordChangeRequest;
 import doit.apihw.api.controller.dto.MemberResponse;
+import doit.apihw.api.controller.dto.NewNameRequest;
 import doit.apihw.api.service.MemberService;
 import java.util.List;
 import lombok.RequiredArgsConstructor;
@@ -23,6 +24,7 @@ public class MemberController {
      */
     @GetMapping("/members/{memberId}")
     public MemberResponse findOneMember(@PathVariable Long memberId) {
+
         return memberService.findOneMember(memberId);
     }
 
@@ -51,5 +53,8 @@ public void changePassword(@PathVariable Long memberId, @RequestBody AuthPasswor
     }
 
     // TODO : 자유 주제로 API를 추가로 구현해보세요.
-
+    @PostMapping("/members/{memberId}/name")
+    public void changeName(@PathVariable Long memberId, @RequestBody NewNameRequest request){
+        memberService.changeName(memberId, request);
+    }
 }
diff --git a/src/main/java/doit/apihw/api/controller/dto/NewNameRequest.java b/src/main/java/doit/apihw/api/controller/dto/NewNameRequest.java
new file mode 100644
index 0000000..fbce984
--- /dev/null
+++ b/src/main/java/doit/apihw/api/controller/dto/NewNameRequest.java
@@ -0,0 +1,8 @@
+package doit.apihw.api.controller.dto;
+
+import lombok.Data;
+
+@Data
+public class NewNameRequest {
+    String newname;
+}
diff --git a/src/main/java/doit/apihw/api/service/AuthService.java b/src/main/java/doit/apihw/api/service/AuthService.java
index ca3dd9d..19ecad5 100644
--- a/src/main/java/doit/apihw/api/service/AuthService.java
+++ b/src/main/java/doit/apihw/api/service/AuthService.java
@@ -1,9 +1,6 @@
 package doit.apihw.api.service;
 
-import doit.apihw.api.controller.dto.AuthLoginRequest;
-import doit.apihw.api.controller.dto.AuthLoginResponse;
-import doit.apihw.api.controller.dto.AuthPasswordChangeRequest;
-import doit.apihw.api.controller.dto.AuthSignUpRequest;
+import doit.apihw.api.controller.dto.*;
 import doit.apihw.domain.member.Member;
 import doit.apihw.domain.member.MemberRepository;
 import lombok.RequiredArgsConstructor;
@@ -52,11 +49,15 @@ public AuthLoginResponse signUp(AuthSignUpRequest request) {
     // TODO : 로그인을 진행한다.
     public AuthLoginResponse login(AuthLoginRequest request) {
         // DB에서 memberLoginId와 memberPassword를 조회하여 일치하는 회원이 있는지 확인한다.
+        Member member = memberRepository.findByMemberLoginId(request.getMemberLoginId());
 
         // 만약 일치하는 회원이 없다면, IllegalArgumentException을 발생시킨다.
+        if(member == null){
+            throw new IllegalArgumentException("존재하지 않는 아이디입니다.");
+        }
 
         // 일치하는 회원이 있다면, MemberResponse로 변환하여 반환한다.
-        return null;
+        return AuthLoginResponse.from(member);
     }
 
 
diff --git a/src/main/java/doit/apihw/api/service/MemberService.java b/src/main/java/doit/apihw/api/service/MemberService.java
index dc31790..4c4670c 100644
--- a/src/main/java/doit/apihw/api/service/MemberService.java
+++ b/src/main/java/doit/apihw/api/service/MemberService.java
@@ -2,6 +2,7 @@
 
 import doit.apihw.api.controller.dto.AuthPasswordChangeRequest;
 import doit.apihw.api.controller.dto.MemberResponse;
+import doit.apihw.api.controller.dto.NewNameRequest;
 import doit.apihw.domain.member.Member;
 import doit.apihw.domain.member.MemberRepository;
 import java.time.LocalDate;
@@ -31,26 +32,48 @@ public MemberResponse findOneMember(Long memberId) {
     // TODO : 전체 회원 정보를 조회한다.
     public List<MemberResponse> findAllMembers() {
         // DB에서 전체 회원 정보를 조회한다.
-
+        List<Member> members = memberRepository.findAll();
         // 조회된 회원 정보를 List<MemberResponse>로 변환하여 반환한다.
-        return null;
+        if(members.isEmpty())
+            throw new IllegalArgumentException("회원이 없음");
+
+        return members.stream()
+                .map(MemberResponse::from)
+                .toList();
     }
 
     // TODO : 회원 이름으로 회원 정보를 조회한다.
     public List<MemberResponse> searchMembersWithName(String memberName) {
         // DB에서 memberName에 해당하는 회원 정보를 조회한다.
+        List<Member> members = memberRepository.findByMemberName(memberName);
+        if(members==null)
+            throw new IllegalArgumentException("해당 회원이 없어여");
 
         // 조회된 회원 정보를 List<MemberResponse>로 변환하여 반환한다.
-        return null;
+        return members.stream()
+                .map(MemberResponse::from)
+                .toList();
     }
 
     // TODO : 회원 비밀번호를 변경한다.
     public void changePassword(Long memberId, AuthPasswordChangeRequest request) {
         // DB에서 memberId에 해당하는 회원 정보를 조회하고, 존재하지 않는다면 IllegalArgumentException을 발생시킨다.
-
+        Member member = memberRepository.findByIdAndMemberPassword(memberId, request.getOldPassword());
+        if(member==null)
+            throw new IllegalArgumentException("비번을 바꾼다고? 너 누군데");
         // 조회된 회원 정보의 비밀번호를 변경한다. ( request.getNewPassword()를 이용하여 변경한다. )
-
+        member.changePassword(request.getOldPassword(),request.getNewPassword());
         // 변경된 회원 정보를 DB에 저장한다.
+        memberRepository.save(member);
+;    }
+
+    // 이름 바꾸기
+    public void changeName(Long memberId, NewNameRequest request){
+        Optional<Member> member = memberRepository.findById(memberId);
+        if(member.isEmpty())
+            throw new IllegalArgumentException("넌 무슨 이름을 바꾼다는 말을");
+        member.get().changeName(request.getNewname());
+        memberRepository.save(member.get());
     }
 
 }
diff --git a/src/main/java/doit/apihw/domain/member/Member.java b/src/main/java/doit/apihw/domain/member/Member.java
index cb60b39..beb4e38 100644
--- a/src/main/java/doit/apihw/domain/member/Member.java
+++ b/src/main/java/doit/apihw/domain/member/Member.java
@@ -38,4 +38,10 @@ public void changePassword(String oldPassword, String newPassword) {
         }
         memberPassword = newPassword;
     }
+
+    public void changeName(String name){
+        if(name.equals(memberName))
+            throw new RuntimeException("뭘 바꾸겠다는건데");
+        memberName = name;
+    }
 }
diff --git a/src/main/java/doit/apihw/domain/member/MemberRepository.java b/src/main/java/doit/apihw/domain/member/MemberRepository.java
index a795758..d260c10 100644
--- a/src/main/java/doit/apihw/domain/member/MemberRepository.java
+++ b/src/main/java/doit/apihw/domain/member/MemberRepository.java
@@ -2,10 +2,14 @@
 
 import org.springframework.data.jpa.repository.JpaRepository;
 
+import java.util.List;
+
 public interface MemberRepository extends JpaRepository<Member, Long> {
     Member findByMemberLoginId(String memberLoginId);
     // TODO : 회원 이름으로 회원 정보를 조회한다.
-
+    List<Member> findByMemberName(String memberName); // 반환 타입 Member -> List<Member>
     // TODO : 회원 로그인 ID와 비밀번호로 회원 정보를 조회한다.
+    Member findByIdAndMemberPassword(Long loginId, String password);
+
 
 }