diff --git a/docs/CHANGELOG.md b/docs/CHANGELOG.md
index 0ba4a75d..56b7d55f 100644
--- a/docs/CHANGELOG.md
+++ b/docs/CHANGELOG.md
@@ -16,7 +16,7 @@
 
 **Changed**
 
-- change: generate pytest in chain style by default
+- change: har2case generate pytest file by default
 - docs: update sponsor info
 
 ## 3.0.6 (2020-05-29)
diff --git a/httprunner/ext/har2case/__init__.py b/httprunner/ext/har2case/__init__.py
index 3847d7c3..ade2ac36 100644
--- a/httprunner/ext/har2case/__init__.py
+++ b/httprunner/ext/har2case/__init__.py
@@ -30,7 +30,14 @@ def init_har2case_parser(subparsers):
         "--to-yaml",
         dest="to_yaml",
         action="store_true",
-        help="Convert to YAML format, if not specified, convert to JSON format by default.",
+        help="Convert to YAML format, if not specified, convert to pytest format by default.",
+    )
+    parser.add_argument(
+        "-2j",
+        "--to-json",
+        dest="to_json",
+        action="store_true",
+        help="Convert to JSON format, if not specified, convert to pytest format by default.",
     )
     parser.add_argument(
         "--filter",
@@ -55,7 +62,13 @@ def main_har2case(args):
         logger.error(f"HAR file not exists: {har_source_file}")
         sys.exit(1)
 
-    output_file_type = "YML" if args.to_yaml else "JSON"
+    if args.to_yaml:
+        output_file_type = "YAML"
+    elif args.to_yaml:
+        output_file_type = "JSON"
+    else:
+        output_file_type = "pytest"
+
     HarParser(har_source_file, args.filter, args.exclude).gen_testcase(output_file_type)
 
     return 0
diff --git a/httprunner/ext/har2case/core.py b/httprunner/ext/har2case/core.py
index 3130a91c..56d14464 100644
--- a/httprunner/ext/har2case/core.py
+++ b/httprunner/ext/har2case/core.py
@@ -7,6 +7,7 @@ import urllib.parse as urlparse
 from loguru import logger
 
 from httprunner.ext.har2case import utils
+from httprunner.make import make_testcase, format_pytest_with_black
 
 try:
     from json.decoder import JSONDecodeError
@@ -329,17 +330,23 @@ class HarParser(object):
         testcase = {"config": config, "teststeps": teststeps}
         return testcase
 
-    def gen_testcase(self, file_type="JSON"):
+    def gen_testcase(self, file_type="pytest"):
         logger.info(f"Start to generate testcase from {self.har_file_path}")
         harfile = os.path.splitext(self.har_file_path)[0]
-        output_testcase_file = "{}.{}".format(harfile, file_type.lower())
 
         testcase = self._make_testcase()
         logger.debug("prepared testcase: {}".format(testcase))
 
         if file_type == "JSON":
+            output_testcase_file = f"{harfile}.json"
             utils.dump_json(testcase, output_testcase_file)
-        else:
+        elif file_type == "YAML":
+            output_testcase_file = f"{harfile}.yml"
             utils.dump_yaml(testcase, output_testcase_file)
+        else:
+            # default to generate pytest file
+            testcase["config"]["path"] = self.har_file_path
+            output_testcase_file = make_testcase(testcase)
+            format_pytest_with_black(output_testcase_file)
 
         logger.info(f"generated testcase: {output_testcase_file}")
diff --git a/httprunner/make.py b/httprunner/make.py
index 43c250d5..a43be11f 100644
--- a/httprunner/make.py
+++ b/httprunner/make.py
@@ -110,7 +110,7 @@ def convert_testcase_path(testcase_path: Text) -> Tuple[Text, Text]:
     raw_file_name, file_suffix = os.path.splitext(os.path.basename(testcase_path))
 
     file_suffix = file_suffix.lower()
-    if file_suffix not in [".json", ".yml", ".yaml"]:
+    if file_suffix not in [".json", ".yml", ".yaml", ".har"]:
         raise exceptions.ParamsError(
             "testcase file should have .yaml/.yml/.json suffix"
         )
@@ -125,7 +125,7 @@ def convert_testcase_path(testcase_path: Text) -> Tuple[Text, Text]:
     return testcase_python_path, name_in_title_case
 
 
-def format_pytest_with_black(python_paths: List[Text]) -> NoReturn:
+def format_pytest_with_black(*python_paths: Text) -> NoReturn:
     logger.info("format pytest cases with black ...")
     try:
         subprocess.run(["black", *python_paths])
@@ -231,14 +231,14 @@ def make_teststep_chain_style(teststep: Dict) -> Text:
             expect = validator["expect"]
             if isinstance(expect, Text):
                 expect = f'"{expect}"'
-            step_info += f'.assert_{assert_method}({check}, {expect})'
+            step_info += f".assert_{assert_method}({check}, {expect})"
 
     return f"Step({step_info})"
 
 
 def make_testcase(
     testcase: Dict, dir_path: Text = None, ref_flag: bool = False,
-) -> NoReturn:
+) -> Text:
     """convert valid testcase dict to pytest file path"""
     # ensure compatibility with testcase format v2
     testcase = ensure_testcase_v3(testcase)
@@ -257,7 +257,7 @@ def make_testcase(
 
     global make_files_cache_set
     if testcase_python_path in make_files_cache_set:
-        return
+        return testcase_python_path
 
     config = testcase["config"]
     config["path"] = __ensure_cwd_relative(testcase_python_path)
@@ -317,6 +317,8 @@ def make_testcase(
     if not ref_flag:
         make_files_cache_set.add(__ensure_cwd_relative(testcase_python_path))
 
+    return testcase_python_path
+
 
 def make_testsuite(testsuite: Dict) -> NoReturn:
     """convert valid testsuite dict to pytest folder with testcases"""
@@ -424,7 +426,7 @@ def main_make(tests_paths: List[Text]) -> List[Text]:
         __make(tests_path)
 
     testcase_path_list = list(make_files_cache_set)
-    format_pytest_with_black(testcase_path_list)
+    format_pytest_with_black(*testcase_path_list)
     return testcase_path_list