diff --git a/src/main/java/coffeemeet/server/auth/controller/AuthController.java b/src/main/java/coffeemeet/server/auth/controller/AuthController.java
index 7ced79a7..77853a38 100644
--- a/src/main/java/coffeemeet/server/auth/controller/AuthController.java
+++ b/src/main/java/coffeemeet/server/auth/controller/AuthController.java
@@ -6,6 +6,7 @@
 import coffeemeet.server.user.domain.OAuthProvider;
 import jakarta.servlet.http.HttpServletResponse;
 import java.io.IOException;
+import java.util.Optional;
 import lombok.RequiredArgsConstructor;
 import org.springframework.http.HttpStatus;
 import org.springframework.http.ResponseEntity;
@@ -14,6 +15,7 @@
 import org.springframework.web.bind.annotation.PostMapping;
 import org.springframework.web.bind.annotation.RequestBody;
 import org.springframework.web.bind.annotation.RequestMapping;
+import org.springframework.web.bind.annotation.RequestParam;
 import org.springframework.web.bind.annotation.RestController;
 
 @RestController
@@ -28,7 +30,6 @@ public ResponseEntity<Void> redirectAuthCodeRequestUrl(@PathVariable OAuthProvid
       HttpServletResponse response) throws IOException {
     String redirectUrl = authService.getAuthCodeRequestUrl(oAuthProvider);
     response.sendRedirect(redirectUrl);
-
     return new ResponseEntity<>(HttpStatus.FOUND);
   }
 
@@ -37,4 +38,17 @@ public ResponseEntity<AuthTokens> signup(@RequestBody SignupRequest request) {
     return ResponseEntity.ok(authService.signup(request));
   }
 
+  @GetMapping("/login/{oAuthProvider}")
+  public ResponseEntity<?> login(@PathVariable OAuthProvider oAuthProvider,
+      @RequestParam String authCode, HttpServletResponse response) throws IOException {
+    Optional<AuthTokens> authTokens = authService.login(oAuthProvider, authCode);
+    if (authTokens.isPresent()) {
+      return ResponseEntity.ok(authTokens.get());
+    }
+
+    String signupUrl = "/oauth2/auth/sign-up";
+    response.sendRedirect(signupUrl);
+    return new ResponseEntity<>(HttpStatus.FOUND);
+  }
+
 }
diff --git a/src/main/java/coffeemeet/server/auth/service/AuthService.java b/src/main/java/coffeemeet/server/auth/service/AuthService.java
index cde3a740..5b0e7b6c 100644
--- a/src/main/java/coffeemeet/server/auth/service/AuthService.java
+++ b/src/main/java/coffeemeet/server/auth/service/AuthService.java
@@ -16,6 +16,7 @@
 import coffeemeet.server.user.repository.UserRepository;
 import java.util.ArrayList;
 import java.util.List;
+import java.util.Optional;
 import lombok.RequiredArgsConstructor;
 import org.springframework.stereotype.Service;
 
@@ -62,6 +63,13 @@ public AuthTokens signup(SignupRequest request) {
     return authTokensGenerator.generate(newUser.getId());
   }
 
+  public Optional<AuthTokens> login(OAuthProvider oAuthProvider, String authCode) {
+    OAuthInfoResponse response = oauthMemberClientComposite.fetch(oAuthProvider, authCode);
+    Optional<User> foundUser = userRepository.getUserByOauthInfoOauthProviderAndOauthInfoOauthProviderId(
+        response.oAuthProvider(), response.oAuthProviderId());
+    return foundUser.map(user -> authTokensGenerator.generate(user.getId()));
+  }
+
   private void checkDuplicateUser(OAuthInfoResponse response) {
     if (userRepository.existsUserByOauthInfo_oauthProviderAndOauthInfo_oauthProviderId(
         response.oAuthProvider(), response.oAuthProviderId())) {
diff --git a/src/main/java/coffeemeet/server/user/domain/ReportInfo.java b/src/main/java/coffeemeet/server/user/domain/ReportInfo.java
index 1bf0c209..5e920b75 100644
--- a/src/main/java/coffeemeet/server/user/domain/ReportInfo.java
+++ b/src/main/java/coffeemeet/server/user/domain/ReportInfo.java
@@ -3,13 +3,10 @@
 import jakarta.persistence.Column;
 import jakarta.persistence.Embeddable;
 import java.time.LocalDateTime;
-import lombok.AccessLevel;
 import lombok.Getter;
-import lombok.NoArgsConstructor;
 
 @Getter
 @Embeddable
-@NoArgsConstructor(access = AccessLevel.PROTECTED)
 public class ReportInfo {
 
   private static final int REPORT_MIN_COUNT = 0;
@@ -17,26 +14,11 @@ public class ReportInfo {
   @Column(nullable = false)
   private int reportedCount;
 
-  @Column(nullable = false)
   private LocalDateTime sanctionPeriod;
 
-  public ReportInfo(int reportedCount, LocalDateTime sanctionPeriod) {
-    validateReportedCount(reportedCount);
-    validateSanctionPeriod(sanctionPeriod);
-    this.reportedCount = reportedCount;
-    this.sanctionPeriod = sanctionPeriod;
-  }
-
-  private void validateReportedCount(int reportedCount) {
-    if (reportedCount < REPORT_MIN_COUNT) {
-      throw new IllegalArgumentException("올바르지 않은 신고횟수입니다.");
-    }
-  }
-
-  private void validateSanctionPeriod(LocalDateTime sanctionPeriod) {
-    if (sanctionPeriod == null) {
-      throw new IllegalArgumentException("올바르지 않은 제재 기간입니다.");
-    }
+  public ReportInfo() {
+    this.reportedCount = REPORT_MIN_COUNT;
+    this.sanctionPeriod = null;
   }
 
 }
diff --git a/src/main/java/coffeemeet/server/user/domain/User.java b/src/main/java/coffeemeet/server/user/domain/User.java
index 811aa3d9..ca575d69 100644
--- a/src/main/java/coffeemeet/server/user/domain/User.java
+++ b/src/main/java/coffeemeet/server/user/domain/User.java
@@ -36,11 +36,10 @@ public class User extends AdvancedBaseEntity {
   private Profile profile;
 
   @ManyToOne
-  @JoinColumn(name = "chatting_room_id", nullable = false)
+  @JoinColumn(name = "chatting_room_id")
   private ChattingRoom chattingRoom;
 
   @Embedded
-  @Column(nullable = false)
   private Certification certification;
 
   @Embedded
@@ -56,6 +55,8 @@ public User(
   ) {
     this.oauthInfo = oauthInfo;
     this.profile = profile;
+    this.certification = new Certification();
+    this.reportInfo = new ReportInfo();
   }
 
   public void updateBusinessCardUrl(String newBusinessCardUrl) {
diff --git a/src/main/java/coffeemeet/server/user/repository/UserRepository.java b/src/main/java/coffeemeet/server/user/repository/UserRepository.java
index a83cdb69..90da80fb 100644
--- a/src/main/java/coffeemeet/server/user/repository/UserRepository.java
+++ b/src/main/java/coffeemeet/server/user/repository/UserRepository.java
@@ -2,6 +2,7 @@
 
 import coffeemeet.server.user.domain.OAuthProvider;
 import coffeemeet.server.user.domain.User;
+import java.util.Optional;
 import org.springframework.data.jpa.repository.JpaRepository;
 
 public interface UserRepository extends JpaRepository<User, Long> {
@@ -10,4 +11,7 @@ boolean existsUserByOauthInfo_oauthProviderAndOauthInfo_oauthProviderId(
       OAuthProvider oauthProvider,
       String oauthProviderId);
 
+  Optional<User> getUserByOauthInfoOauthProviderAndOauthInfoOauthProviderId(
+      OAuthProvider oAuthProvider,
+      String authCode);
 }