diff --git a/README.md b/README.md
index 851d0efa..452722d2 100644
--- a/README.md
+++ b/README.md
@@ -15,7 +15,7 @@ HttpBoomer is a golang implementation of [HttpRunner]. Ideally, HttpBoomer will
 ![flow chart](docs/flow.jpg)
 
 - [x] Full support for HTTP(S) requests, more protocols are also in the plan.
-- [ ] Testcases can be described in multiple formats, `YAML`/`JSON`/`Golang`, and they are interchangeable.
+- [x] Testcases can be described in multiple formats, `YAML`/`JSON`/`Golang`, and they are interchangeable.
 - [ ] With [`HAR`][HAR] support, you can use Charles/Fiddler/Chrome/etc as a script recording generator.
 - [x] Supports `variables`/`extract`/`validate`/`hooks` mechanisms to create extremely complex test scenarios.
 - [ ] Built-in integration of rich functions, and you can also use [`go plugin`][plugin] to create and call custom functions.
diff --git a/convert.go b/convert.go
index 80280226..c99d2bb7 100644
--- a/convert.go
+++ b/convert.go
@@ -3,6 +3,7 @@ package httpboomer
 import (
 	"bytes"
 	"encoding/json"
+	"fmt"
 	"io/ioutil"
 	"log"
 	"path/filepath"
@@ -124,3 +125,29 @@ func convertTestCase(tc *TCase) (*TestCase, error) {
 	}
 	return testCase, nil
 }
+
+var ErrUnsupportedFileExt = fmt.Errorf("unsupported testcase file extension")
+
+func loadTestFile(path *TestCasePath) (*TestCase, error) {
+	var tc *TCase
+	var err error
+
+	casePath := path.string
+	ext := filepath.Ext(casePath)
+	switch ext {
+	case ".json":
+		tc, err = loadFromJSON(casePath)
+	case ".yaml", ".yml":
+		tc, err = loadFromYAML(casePath)
+	default:
+		err = ErrUnsupportedFileExt
+	}
+	if err != nil {
+		return nil, err
+	}
+	testcase, err := convertTestCase(tc)
+	if err != nil {
+		return nil, err
+	}
+	return testcase, nil
+}
diff --git a/convert_test.go b/convert_test.go
index 8b9dbb9e..9abd788c 100644
--- a/convert_test.go
+++ b/convert_test.go
@@ -50,7 +50,7 @@ var demoTestCase = &TestCase{
 }
 
 func TestDumpAndLoadJSON(t *testing.T) {
-	jsonPath := "demo.json"
+	jsonPath := demoTestCaseJSONPath
 	err := demoTestCase.dump2JSON(jsonPath)
 	if !assert.NoError(t, err) {
 		t.Fail()
@@ -94,13 +94,11 @@ func TestDumpAndLoadYAML(t *testing.T) {
 	}
 }
 
+var demoTestCaseJSONPath = "demo.json"
+
 func TestLoadJSONAndRun(t *testing.T) {
-	jsonPath := "demo.json"
-	tc, err := loadFromJSON(jsonPath)
-	if !assert.NoError(t, err) {
-		t.Fail()
-	}
-	testcase, err := convertTestCase(tc)
+	jsonPath := &TestCasePath{demoTestCaseJSONPath}
+	testcase, err := loadTestFile(jsonPath)
 	if !assert.NoError(t, err) {
 		t.Fail()
 	}
diff --git a/models.go b/models.go
index 8b0e8e75..87e67f29 100644
--- a/models.go
+++ b/models.go
@@ -67,12 +67,32 @@ type IStep interface {
 	ToStruct() *TStep
 }
 
+type ITestCase interface {
+	ToStruct() (*TestCase, error)
+}
+
 // used for testcase runner
 type TestCase struct {
 	Config    TConfig
 	TestSteps []IStep
 }
 
+func (tc *TestCase) ToStruct() (*TestCase, error) {
+	return tc, nil
+}
+
+type TestCasePath struct {
+	string
+}
+
+func (path *TestCasePath) ToStruct() (*TestCase, error) {
+	testcase, err := loadTestFile(path)
+	if err != nil {
+		return nil, err
+	}
+	return testcase, nil
+}
+
 type TestCaseSummary struct{}
 
 type StepData struct {
diff --git a/runner.go b/runner.go
index 6565f120..43a99005 100644
--- a/runner.go
+++ b/runner.go
@@ -8,7 +8,7 @@ import (
 	"github.com/imroc/req"
 )
 
-func Test(t *testing.T, testcases ...*TestCase) error {
+func Test(t *testing.T, testcases ...ITestCase) error {
 	return NewRunner().WithTestingT(t).SetDebug(true).Run(testcases...)
 }
 
@@ -36,9 +36,15 @@ func (r *Runner) SetDebug(debug bool) *Runner {
 	return r
 }
 
-func (r *Runner) Run(testcases ...*TestCase) error {
+func (r *Runner) Run(testcases ...ITestCase) error {
 	for _, testcase := range testcases {
-		if err := r.runCase(testcase); err != nil {
+		tcStruct, err := testcase.ToStruct()
+		if err != nil {
+			log.Printf("[Run] testcase.ToStruct() error: %v", err)
+			return err
+		}
+		if err := r.runCase(tcStruct); err != nil {
+			log.Printf("[Run] runCase error: %v", err)
 			return err
 		}
 	}
diff --git a/runner_test.go b/runner_test.go
index 8a490e23..fbd180e8 100644
--- a/runner_test.go
+++ b/runner_test.go
@@ -1,6 +1,7 @@
 package httpboomer
 
 import (
+	"os"
 	"testing"
 )
 
@@ -30,9 +31,29 @@ func TestHttpRunner(t *testing.T) {
 			Weight: 3,
 		},
 	}
+	testcase3 := &TestCasePath{demoTestCaseJSONPath}
 
-	err := Test(t, testcase1, testcase2)
+	err := Test(t, testcase1, testcase2, testcase3)
 	if err != nil {
 		t.Fatalf("run testcase error: %v", err)
 	}
 }
+
+func TestMain(m *testing.M) {
+	// setup, prepare demo json testcase file path
+	jsonPath := demoTestCaseJSONPath
+	err := demoTestCase.dump2JSON(jsonPath)
+	if err != nil {
+		os.Exit(1)
+	}
+
+	// run all tests
+	code := m.Run()
+	defer os.Exit(code)
+
+	// teardown
+	err = os.Remove(jsonPath)
+	if err != nil {
+		os.Exit(1)
+	}
+}