diff --git a/BE/src/auth/users.repository.ts b/BE/src/auth/users.repository.ts
index c5bf786..e77c642 100644
--- a/BE/src/auth/users.repository.ts
+++ b/BE/src/auth/users.repository.ts
@@ -13,6 +13,17 @@ export class UsersRepository {
 
     const salt = await bcrypt.genSalt();
     const hashedPassword = await bcrypt.hash(password, salt);
+
+    const userIdDuplicate = await User.findOne({ where: { userId: userId } });
+    if (userIdDuplicate) {
+      throw new ConflictException("중복된 아이디입니다.");
+    }
+
+    const emailDuplicate = await User.findOne({ where: { email: email } });
+    if (emailDuplicate) {
+      throw new ConflictException("중복된 이메일입니다.");
+    }
+
     const user = User.create({
       userId,
       password: hashedPassword,