diff --git a/pkg/cloudcommon/db/metadata.go b/pkg/cloudcommon/db/metadata.go
index 289e0aae20..f0d99a74da 100644
--- a/pkg/cloudcommon/db/metadata.go
+++ b/pkg/cloudcommon/db/metadata.go
@@ -117,7 +117,7 @@ func (manager *SMetadataManager) GetPropertyTagValuePairs(ctx context.Context, u
 		Data  []struct {
 			Key   string
 			Value string
-		}
+		} `json:"data,allowempty"`
 	}{
 		Total: 0,
 		Data: []struct {