diff --git a/src/main/kotlin/com/hero/alignlab/domain/auth/resolver/ReactiveUserResolver.kt b/src/main/kotlin/com/hero/alignlab/domain/auth/resolver/ReactiveUserResolver.kt
index 213ab99..5e9afb0 100644
--- a/src/main/kotlin/com/hero/alignlab/domain/auth/resolver/ReactiveUserResolver.kt
+++ b/src/main/kotlin/com/hero/alignlab/domain/auth/resolver/ReactiveUserResolver.kt
@@ -4,6 +4,8 @@ import com.hero.alignlab.domain.auth.application.AuthFacade
 import com.hero.alignlab.domain.auth.model.AUTH_TOKEN_KEY
 import com.hero.alignlab.domain.auth.model.AuthUser
 import com.hero.alignlab.domain.auth.model.AuthUserToken
+import com.hero.alignlab.exception.ErrorCode
+import com.hero.alignlab.exception.NotFoundException
 import org.springframework.core.MethodParameter
 import org.springframework.core.ReactiveAdapterRegistry
 import org.springframework.http.server.reactive.ServerHttpRequest
@@ -40,7 +42,7 @@ class ReactiveUserResolver(
                     .firstOrNull()
                     ?.takeIf { token -> token.isNotBlank() }
                     ?.let { token -> AuthUserToken.from(token) }
-            }.firstOrNull() ?: AuthUserToken.from("")
+            }.firstOrNull() ?: throw NotFoundException(ErrorCode.NOT_FOUND_TOKEN_ERROR)
 
         return authUserToken.toMono()
     }
diff --git a/src/main/kotlin/com/hero/alignlab/exception/ErrorCode.kt b/src/main/kotlin/com/hero/alignlab/exception/ErrorCode.kt
index 85eb824..ae234c7 100644
--- a/src/main/kotlin/com/hero/alignlab/exception/ErrorCode.kt
+++ b/src/main/kotlin/com/hero/alignlab/exception/ErrorCode.kt
@@ -15,6 +15,7 @@ enum class ErrorCode(val status: HttpStatus, val description: String) {
     FAIL_TO_TRANSACTION_TEMPLATE_EXECUTE_ERROR(HttpStatus.BAD_REQUEST, "fail to tx-templates execute error"),
 
     /** Auth Error Code */
+    NOT_FOUND_TOKEN_ERROR(HttpStatus.UNAUTHORIZED, "not found token"),
     FAIL_TO_VERIFY_TOKEN_ERROR(HttpStatus.UNAUTHORIZED, "fail to verify token"),
     INVALID_ACCESS_TOKEN(HttpStatus.UNAUTHORIZED, "유효한 엑세스 토큰이 아닙니다."),
     INVALID_REFRESH_TOKEN(HttpStatus.BAD_REQUEST, "유효한 리프레시 토큰이 아닙니다."),