diff --git a/tools/goctl/api/swagger/parameter.go b/tools/goctl/api/swagger/parameter.go
index 2f5970535..1683161ac 100644
--- a/tools/goctl/api/swagger/parameter.go
+++ b/tools/goctl/api/swagger/parameter.go
@@ -9,7 +9,7 @@ import (
 )
 
 func isPostJson(ctx Context, method string, tp apiSpec.Type) (string, bool) {
-	if strings.EqualFold(method, http.MethodPost) {
+	if !strings.EqualFold(method, http.MethodPost) {
 		return "", false
 	}
 	structType, ok := tp.(apiSpec.DefineStruct)
diff --git a/tools/goctl/api/swagger/parameter_test.go b/tools/goctl/api/swagger/parameter_test.go
new file mode 100644
index 000000000..6c8785508
--- /dev/null
+++ b/tools/goctl/api/swagger/parameter_test.go
@@ -0,0 +1,91 @@
+package swagger
+
+import (
+	"net/http"
+	"testing"
+
+	"github.com/stretchr/testify/assert"
+	apiSpec "github.com/zeromicro/go-zero/tools/goctl/api/spec"
+)
+
+func TestIsPostJson(t *testing.T) {
+	tests := []struct {
+		name     string
+		method   string
+		hasJson  bool
+		expected bool
+	}{
+		{"POST with JSON", http.MethodPost, true, true},
+		{"POST without JSON", http.MethodPost, false, false},
+		{"GET with JSON", http.MethodGet, true, false},
+		{"PUT with JSON", http.MethodPut, true, false},
+	}
+
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			testStruct := createTestStruct("TestStruct", tt.hasJson)
+			_, result := isPostJson(testingContext(t), tt.method, testStruct)
+			assert.Equal(t, tt.expected, result)
+		})
+	}
+}
+
+func TestParametersFromType(t *testing.T) {
+	tests := []struct {
+		name           string
+		method         string
+		useDefinitions bool
+		hasJson        bool
+		expectedCount  int
+		expectedBody   bool
+	}{
+		{"POST JSON with definitions", http.MethodPost, true, true, 1, true},
+		{"POST JSON without definitions", http.MethodPost, false, true, 1, true},
+		{"GET with form", http.MethodGet, false, false, 1, false},
+		{"POST with form", http.MethodPost, false, false, 1, false},
+	}
+
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			ctx := Context{UseDefinitions: tt.useDefinitions}
+			testStruct := createTestStruct("TestStruct", tt.hasJson)
+			params := parametersFromType(ctx, tt.method, testStruct)
+
+			assert.Equal(t, tt.expectedCount, len(params))
+			if tt.expectedBody {
+				assert.Equal(t, paramsInBody, params[0].In)
+			} else if len(params) > 0 {
+				assert.NotEqual(t, paramsInBody, params[0].In)
+			}
+		})
+	}
+}
+
+func TestParametersFromType_EdgeCases(t *testing.T) {
+	ctx := testingContext(t)
+
+	params := parametersFromType(ctx, http.MethodPost, nil)
+	assert.Empty(t, params)
+
+	primitiveType := apiSpec.PrimitiveType{RawName: "string"}
+	params = parametersFromType(ctx, http.MethodPost, primitiveType)
+	assert.Empty(t, params)
+}
+
+func createTestStruct(name string, hasJson bool) apiSpec.DefineStruct {
+	tag := `form:"username"`
+	if hasJson {
+		tag = `json:"username"`
+	}
+
+	return apiSpec.DefineStruct{
+		RawName: name,
+		Members: []apiSpec.Member{
+			{
+				Name: "Username",
+				Type: apiSpec.PrimitiveType{RawName: "string"},
+				Tag:  tag,
+			},
+		},
+	}
+}