diff --git a/src/main/java/com/io/realworld/domain/aggregate/user/controller/UserController.java b/src/main/java/com/io/realworld/domain/aggregate/user/controller/UserController.java
index 6188db1..58b0414 100644
--- a/src/main/java/com/io/realworld/domain/aggregate/user/controller/UserController.java
+++ b/src/main/java/com/io/realworld/domain/aggregate/user/controller/UserController.java
@@ -10,6 +10,7 @@ import com.io.realworld.domain.aggregate.user.service.UserServiceImpl;
 import lombok.AllArgsConstructor;
 import lombok.Value;
 import lombok.extern.slf4j.Slf4j;
+import org.springframework.security.core.Authentication;
 import org.springframework.security.core.annotation.AuthenticationPrincipal;
 import org.springframework.web.bind.annotation.*;
 
@@ -23,7 +24,7 @@ public class UserController {
 
     private final UserServiceImpl userService;
 
-    public UserController(UserServiceImpl userService){
+    public UserController(UserServiceImpl userService) {
         this.userService = userService;
     }
 
@@ -33,7 +34,7 @@ public class UserController {
     }
 
     @PutMapping
-    public UserResponse updateUser(@Valid @RequestBody UserUpdate userUpdate){
-        return userService.updateUser(userUpdate);
+    public UserResponse updateUser(@Valid @RequestBody UserUpdate userUpdate, @AuthenticationPrincipal UserAuth userAuth) {
+        return userService.updateUser(userUpdate, userAuth);
     }
 }
diff --git a/src/main/java/com/io/realworld/domain/aggregate/user/dto/UserUpdate.java b/src/main/java/com/io/realworld/domain/aggregate/user/dto/UserUpdate.java
index 68d9bc7..56c7ae7 100644
--- a/src/main/java/com/io/realworld/domain/aggregate/user/dto/UserUpdate.java
+++ b/src/main/java/com/io/realworld/domain/aggregate/user/dto/UserUpdate.java
@@ -4,18 +4,20 @@ import com.fasterxml.jackson.annotation.JsonTypeInfo;
 import com.fasterxml.jackson.annotation.JsonTypeName;
 import lombok.Builder;
 import lombok.Getter;
+import lombok.Setter;
 import lombok.ToString;
 
 import javax.validation.constraints.Email;
-import javax.validation.constraints.NotBlank;
 
 @Builder
 @Getter
+@Setter
 @ToString
 @JsonTypeName("user")
 @JsonTypeInfo(use = JsonTypeInfo.Id.NAME, include = JsonTypeInfo.As.WRAPPER_OBJECT)
 public class UserUpdate {
 
+    private Long id;
     @Email
     private String email;
     private String username;
diff --git a/src/main/java/com/io/realworld/domain/aggregate/user/entity/User.java b/src/main/java/com/io/realworld/domain/aggregate/user/entity/User.java
index 5b935a0..f94870b 100644
--- a/src/main/java/com/io/realworld/domain/aggregate/user/entity/User.java
+++ b/src/main/java/com/io/realworld/domain/aggregate/user/entity/User.java
@@ -1,5 +1,6 @@
 package com.io.realworld.domain.aggregate.user.entity;
 
+import com.io.realworld.domain.aggregate.user.dto.UserUpdate;
 import lombok.Builder;
 import lombok.Getter;
 import org.springframework.security.core.GrantedAuthority;
@@ -69,4 +70,20 @@ public class User implements UserDetails {
     public boolean isEnabled() {
         return true;
     }
+
+    //비즈니스
+
+    public void changeUsername(String username){
+        this.username = username;
+    }
+
+    public void changeEmail(String email){
+        this.email = email;
+    }
+
+    public void update(UserUpdate userUpdate) {
+        this.password = userUpdate.getPassword();
+        this.bio = userUpdate.getBio();
+        this.image = userUpdate.getImage();
+    }
 }
diff --git a/src/main/java/com/io/realworld/domain/aggregate/user/repository/UserRepository.java b/src/main/java/com/io/realworld/domain/aggregate/user/repository/UserRepository.java
index 277af74..c429445 100644
--- a/src/main/java/com/io/realworld/domain/aggregate/user/repository/UserRepository.java
+++ b/src/main/java/com/io/realworld/domain/aggregate/user/repository/UserRepository.java
@@ -1,11 +1,19 @@
 package com.io.realworld.domain.aggregate.user.repository;
 
 import com.io.realworld.domain.aggregate.user.entity.User;
-import org.springframework.data.repository.CrudRepository;
+import org.springframework.data.jpa.repository.JpaRepository;
+import org.springframework.data.jpa.repository.Modifying;
+
+import java.util.List;
+import java.util.Optional;
 
 
-public interface UserRepository extends CrudRepository<User, Long> {
-    User save(User user);
+public interface UserRepository extends JpaRepository<User, Long> {
     User findByEmail(String email);
-    Iterable<User> findAll();
+    List<User> findAllByEmail(String email);
+
+    Optional<User> findById(Long id);
+
+    Optional<User> findByUsername(String username);
+    List<User> findAll();
 }
diff --git a/src/main/java/com/io/realworld/domain/aggregate/user/service/UserService.java b/src/main/java/com/io/realworld/domain/aggregate/user/service/UserService.java
index 2e844d0..22f2b11 100644
--- a/src/main/java/com/io/realworld/domain/aggregate/user/service/UserService.java
+++ b/src/main/java/com/io/realworld/domain/aggregate/user/service/UserService.java
@@ -10,5 +10,5 @@ public interface UserService {
 
     UserResponse getCurrentUser(UserAuth userAuth);
 
-    UserResponse updateUser(UserUpdate userUpdate);
+    UserResponse updateUser(UserUpdate userUpdate, UserAuth userAuth);
 }
diff --git a/src/main/java/com/io/realworld/domain/aggregate/user/service/UserServiceImpl.java b/src/main/java/com/io/realworld/domain/aggregate/user/service/UserServiceImpl.java
index 801adee..49e9b22 100644
--- a/src/main/java/com/io/realworld/domain/aggregate/user/service/UserServiceImpl.java
+++ b/src/main/java/com/io/realworld/domain/aggregate/user/service/UserServiceImpl.java
@@ -8,12 +8,14 @@ import com.io.realworld.domain.aggregate.user.entity.User;
 import com.io.realworld.domain.aggregate.user.repository.UserRepository;
 import lombok.RequiredArgsConstructor;
 
+import lombok.extern.log4j.Log4j2;
 import org.springframework.security.crypto.password.PasswordEncoder;
 import org.springframework.stereotype.Service;
 import org.springframework.transaction.annotation.Transactional;
 
 @Service
 @RequiredArgsConstructor
+@Log4j2
 @Transactional(readOnly = true)
 public class UserServiceImpl implements UserService {
 
@@ -55,20 +57,39 @@ public class UserServiceImpl implements UserService {
         if (findUser == null) {
             throw new CustomException(Error.EMAIL_NULL_OR_INVALID);
         } else {
+            System.out.println(findUser);
             return convertUser(findUser);
         }
     }
 
     @Override
-    public UserResponse updateUser(UserUpdate userUpdate){
-        System.out.println(userUpdate.toString());
-        userRepository.save(User.builder()
-                .username(userUpdate.getUsername())
-                .image(userUpdate.getImage())
-                .bio(userUpdate.getBio())
-                .password(userUpdate.getPassword())
-                .email(userUpdate.getEmail()).build());
-        return convertUser();
+    @Transactional
+    public UserResponse updateUser(UserUpdate userUpdate, UserAuth userAuth){
+        User user = userRepository.findById(userAuth.getId()).orElseThrow(() -> new CustomException(Error.USER_NOT_FOUND));
+
+        if(userUpdate.getUsername() != null){
+            userRepository.findByUsername(userUpdate.getUsername())
+                    .filter(found -> !found.getId().equals(userRepository.findById(user.getId())))
+                    .ifPresent(found -> new CustomException(Error.DUPLICATE_USER));
+            System.out.println(user.getUsername() + userUpdate.getUsername());
+            user.changeUsername(userUpdate.getUsername());
+            System.out.println("!!" + user.getUsername() );
+        }
+
+        if(userUpdate.getEmail() != null){
+            userRepository.findAllByEmail(userUpdate.getEmail())
+                    .stream().filter(found -> !found.getId().equals(userRepository.findById(user.getId())))
+                        .findAny().ifPresent(found -> new CustomException(Error.DUPLICATE_USER));
+            user.changeEmail(userUpdate.getEmail());
+        }
+        userUpdate.setId(user.getId());
+        user.update(userUpdate);
+
+        log.info(" {} , {} {}",userUpdate.hashCode(),  user.hashCode() , user.getId());
+        User test = userRepository.save(user);
+        log.info("test : {}",test.getBio());
+
+        return convertUser(test);
     }
 
 
diff --git a/src/main/java/com/io/realworld/exception/Error.java b/src/main/java/com/io/realworld/exception/Error.java
index e286b48..378e78d 100644
--- a/src/main/java/com/io/realworld/exception/Error.java
+++ b/src/main/java/com/io/realworld/exception/Error.java
@@ -7,7 +7,9 @@ import org.springframework.http.HttpStatus;
 public enum Error {
     DUPLICATE_USER("duplicate user", HttpStatus.CONFLICT),
     SIGNUP_NULL_DATA("request body include null",HttpStatus.BAD_REQUEST),
-    EMAIL_NULL_OR_INVALID("email is blank or invalid check plz",HttpStatus.BAD_REQUEST);
+    EMAIL_NULL_OR_INVALID("email is blank or invalid check plz",HttpStatus.BAD_REQUEST),
+    USER_NOT_FOUND("user not found check your info",HttpStatus.NOT_FOUND);
+
 
     private final String message;
     private final HttpStatus status;