diff --git a/e2e/plugin/plugin_test.go b/e2e/plugin/plugin_test.go
index 5a3e5d5c0..1c9892bee 100644
--- a/e2e/plugin/plugin_test.go
+++ b/e2e/plugin/plugin_test.go
@@ -140,6 +140,12 @@ var _ = Describe("Test Kubectl Plugin", func() {
 			Expect(output).Should(ContainSubstring("targetPort"))
 			Expect(output).Should(ContainSubstring("target port num for service provider."))
 		})
+		It("Test show traitDefinition def with cue single map parameter", func() {
+			tdName := "annotations"
+			output, err := e2e.Exec(fmt.Sprintf("kubectl-vela show %s", tdName))
+			Expect(err).NotTo(HaveOccurred())
+			Expect(output).Should(ContainSubstring("map[string]string"))
+		})
 	})
 
 	Context("Test kubectl vela comp discover", func() {
diff --git a/references/plugins/references.go b/references/plugins/references.go
index 163b36aa0..b452d8b75 100644
--- a/references/plugins/references.go
+++ b/references/plugins/references.go
@@ -536,6 +536,17 @@ func (ref *ParseReference) parseParameters(paraValue cue.Value, paramKey string,
 		if err != nil {
 			return fmt.Errorf("arguments not defined as struct %w", err)
 		}
+		if arguments.Len() == 0 {
+			var param ReferenceParameter
+			param.Name = "undefined"
+			param.Required = true
+			tl := paraValue.Template()
+			if tl != nil { // is map type
+				param.PrintableType = fmt.Sprintf("map[string]%s", tl("").IncompleteKind().String())
+			}
+			params = append(params, param)
+		}
+
 		for i := 0; i < arguments.Len(); i++ {
 			var param ReferenceParameter
 			fi := arguments.Field(i)