diff --git a/README.md b/README.md
index 77b01835..933acc4a 100644
--- a/README.md
+++ b/README.md
@@ -1,6 +1,6 @@
 ## 개발 환경 설정
 
-[AWS API SERVER](http://ec2-13-209-127-186.ap-northeast-2.compute.amazonaws.com)
+[AWS API SERVER](http://ec2-13-209-127-186.ap-northeast-2.compute.amazonaws.com:8080)
 ---
 
 * 루트 디렉토리(WEB3_4_Log4U_BE)에서 다음 명령 실행
diff --git a/src/main/java/com/example/log4u/common/oauth2/controller/OAuth2Controller.java b/src/main/java/com/example/log4u/common/oauth2/controller/OAuth2Controller.java
index 5ab48af9..096614ed 100644
--- a/src/main/java/com/example/log4u/common/oauth2/controller/OAuth2Controller.java
+++ b/src/main/java/com/example/log4u/common/oauth2/controller/OAuth2Controller.java
@@ -6,8 +6,8 @@
 import org.springframework.web.bind.annotation.RequestMapping;
 import org.springframework.web.bind.annotation.RestController;
 
+import com.example.log4u.common.constants.TokenConstants;
 import com.example.log4u.common.oauth2.jwt.JwtUtil;
-import com.example.log4u.common.oauth2.repository.RefreshTokenRepository;
 import com.example.log4u.common.oauth2.service.RefreshTokenService;
 
 import io.jsonwebtoken.ExpiredJwtException;
@@ -23,7 +23,6 @@ public class OAuth2Controller {
 
 	private final JwtUtil jwtUtil;
 	private final RefreshTokenService refreshTokenService;
-	private final RefreshTokenRepository refreshTokenRepository;
 
 	@GetMapping("/token/reissue")
 	public ResponseEntity<?> reissue(
@@ -35,10 +34,10 @@ public ResponseEntity<?> reissue(
 		String access = null;
 		Cookie[] cookies = request.getCookies();
 		for (Cookie cookie : cookies) {
-			if (cookie.getName().equals("refresh")) {
+			if (cookie.getName().equals(TokenConstants.REFRESH_TOKEN)) {
 				refresh = cookie.getValue();
 			}
-			if (cookie.getName().equals("access")) {
+			if (cookie.getName().equals(TokenConstants.ACCESS_TOKEN)) {
 				access = cookie.getValue();
 			}
 		}
@@ -57,7 +56,7 @@ public ResponseEntity<?> reissue(
 
 		// 토큰이 refresh인지 확인 (발급시 페이로드에 명시)
 		String category = jwtUtil.getTokenType(refresh);
-		if (!category.equals("refresh")) {
+		if (!category.equals(TokenConstants.REFRESH_TOKEN)) {
 			return new ResponseEntity<>("잘못된 토큰입니다.", HttpStatus.BAD_REQUEST);
 		}
 
@@ -67,21 +66,20 @@ public ResponseEntity<?> reissue(
 
 	private void createNewTokens(HttpServletResponse response, String access, String refresh) {
 		// 기존 리프레시 토큰 삭제
-		refreshTokenRepository.deleteByRefresh(refresh);
+		refreshTokenService.deleteRefreshToken(refresh);
 
 		Long userId = jwtUtil.getUserId(access);
 		String role = jwtUtil.getRole(access);
 		String name = jwtUtil.getName(access);
 
-		String newAccessToken = jwtUtil.createJwt("access", userId, name, role, 600000L);
-		String newRefreshToken = jwtUtil.createJwt("refresh", userId, name, role, 600000L);
+		String newAccessToken = jwtUtil.createJwt(TokenConstants.ACCESS_TOKEN, userId, name, role, 600000L);
+		String newRefreshToken = jwtUtil.createJwt(TokenConstants.REFRESH_TOKEN, userId, name, role, 600000L);
 
-		response.addCookie(createCookie("refresh", newRefreshToken));
-		response.addCookie(createCookie("access", newAccessToken));
+		response.addCookie(createCookie(TokenConstants.REFRESH_TOKEN, newRefreshToken));
+		response.addCookie(createCookie(TokenConstants.ACCESS_TOKEN, newAccessToken));
 
 		// 새 리프레시 토큰 저장
 		refreshTokenService.saveRefreshToken(
-			userId,
 			name,
 			refresh
 		);
diff --git a/src/main/java/com/example/log4u/common/oauth2/entity/RefreshToken.java b/src/main/java/com/example/log4u/common/oauth2/entity/RefreshToken.java
index 9b050155..6aaf8cb8 100644
--- a/src/main/java/com/example/log4u/common/oauth2/entity/RefreshToken.java
+++ b/src/main/java/com/example/log4u/common/oauth2/entity/RefreshToken.java
@@ -22,7 +22,7 @@ public class RefreshToken {
 	@Setter
 	private String name;
 
-	@Column(nullable = false)
+	@Column(nullable = false, unique = true)
 	@Setter
 	private String refresh;
 
diff --git a/src/main/java/com/example/log4u/common/oauth2/handler/OAuth2AuthenticationSuccessHandler.java b/src/main/java/com/example/log4u/common/oauth2/handler/OAuth2AuthenticationSuccessHandler.java
index 96f6e81d..14208fd0 100644
--- a/src/main/java/com/example/log4u/common/oauth2/handler/OAuth2AuthenticationSuccessHandler.java
+++ b/src/main/java/com/example/log4u/common/oauth2/handler/OAuth2AuthenticationSuccessHandler.java
@@ -76,7 +76,7 @@ private void setCookieAndSaveRefreshToken(
 		String refresh = jwtUtil.createJwt(REFRESH_TOKEN_KEY, userId, name, role, refreshTokenValidityInSeconds);
 
 		// 리프레시 토큰 DB 저장
-		refreshTokenService.saveRefreshToken(null, name, refresh);
+		refreshTokenService.saveRefreshToken(name, refresh);
 
 		response.addCookie(createCookie(ACCESS_TOKEN_KEY, access));
 		response.addCookie(createCookie(REFRESH_TOKEN_KEY, refresh));
diff --git a/src/main/java/com/example/log4u/common/oauth2/service/RefreshTokenService.java b/src/main/java/com/example/log4u/common/oauth2/service/RefreshTokenService.java
index a6c9edb3..43bfcab1 100644
--- a/src/main/java/com/example/log4u/common/oauth2/service/RefreshTokenService.java
+++ b/src/main/java/com/example/log4u/common/oauth2/service/RefreshTokenService.java
@@ -8,6 +8,7 @@
 import com.example.log4u.common.oauth2.entity.RefreshToken;
 import com.example.log4u.common.oauth2.repository.RefreshTokenRepository;
 
+import jakarta.transaction.Transactional;
 import lombok.RequiredArgsConstructor;
 
 @Service
@@ -19,15 +20,20 @@ public class RefreshTokenService {
 	@Value("${jwt.refresh-token-expire-time-seconds}")
 	private long refreshTokenValidityInSeconds;
 
-	public void saveRefreshToken(Long userId, String name, String refresh) {
+	public void saveRefreshToken(String name, String refresh) {
 		Date date = new Date(System.currentTimeMillis() + refreshTokenValidityInSeconds);
 
 		RefreshToken refreshToken = new RefreshToken(
-			userId,
+			null,
 			name,
 			refresh,
 			date.toString()
 		);
 		refreshTokenRepository.save(refreshToken);
 	}
+
+	@Transactional
+	public void deleteRefreshToken(String refresh) {
+		refreshTokenRepository.deleteByRefresh(refresh);
+	}
 }
diff --git a/src/main/resources/application-dev.yml b/src/main/resources/application-dev.yml
index 657b79d4..ba70ea11 100644
--- a/src/main/resources/application-dev.yml
+++ b/src/main/resources/application-dev.yml
@@ -9,6 +9,12 @@ spring:
     hibernate:
       ddl-auto: create
 
+
+    properties:
+      hibernate:
+        format_sql: true
+        show_sql: true
+
   datasource:
     url: jdbc:mysql://localhost:3307/log4u
     username: dev