diff --git a/api/src/main/java/com/alibaba/nacos/api/config/ConfigType.java b/api/src/main/java/com/alibaba/nacos/api/config/ConfigType.java
index d70e2a98d8f..cab303b3598 100644
--- a/api/src/main/java/com/alibaba/nacos/api/config/ConfigType.java
+++ b/api/src/main/java/com/alibaba/nacos/api/config/ConfigType.java
@@ -53,7 +53,12 @@ public enum ConfigType {
     /**
      * config type is "yaml".
      */
-    YAML("yaml");
+    YAML("yaml"),
+    
+    /**
+     * not a real type.
+     */
+    UNSET("unset");
     
     String type;
     
diff --git a/api/src/main/java/com/alibaba/nacos/api/config/annotation/NacosConfigListener.java b/api/src/main/java/com/alibaba/nacos/api/config/annotation/NacosConfigListener.java
index 0025557394a..810833d5928 100644
--- a/api/src/main/java/com/alibaba/nacos/api/config/annotation/NacosConfigListener.java
+++ b/api/src/main/java/com/alibaba/nacos/api/config/annotation/NacosConfigListener.java
@@ -57,9 +57,9 @@
     /**
      * Nacos Config type.
      *
-     * @return "properties"
+     * @return default value is {@link ConfigType#UNSET}
      */
-    ConfigType type() default ConfigType.PROPERTIES;
+    ConfigType type() default ConfigType.UNSET;
     
     /**
      * Specify {@link NacosConfigConverter Nacos configuraion convertor} class to convert target type instance.
diff --git a/api/src/main/java/com/alibaba/nacos/api/config/annotation/NacosConfigurationProperties.java b/api/src/main/java/com/alibaba/nacos/api/config/annotation/NacosConfigurationProperties.java
index 37b6507be89..0e6bc518daa 100644
--- a/api/src/main/java/com/alibaba/nacos/api/config/annotation/NacosConfigurationProperties.java
+++ b/api/src/main/java/com/alibaba/nacos/api/config/annotation/NacosConfigurationProperties.java
@@ -72,9 +72,9 @@
     /**
      * config style.
      *
-     * @return default value is {@link ConfigType#PROPERTIES}
+     * @return default value is {@link ConfigType#UNSET}
      */
-    ConfigType type() default ConfigType.PROPERTIES;
+    ConfigType type() default ConfigType.UNSET;
     
     /**
      * It indicates the properties of current doBind bean is auto-refreshed when Nacos configuration is changed.