diff --git a/httprunner/__about__.py b/httprunner/__about__.py
index 7e565489..aae10f4f 100644
--- a/httprunner/__about__.py
+++ b/httprunner/__about__.py
@@ -1,7 +1,7 @@
 __title__ = 'HttpRunner'
 __description__ = 'One-stop solution for HTTP(S) testing.'
 __url__ = 'https://github.com/HttpRunner/HttpRunner'
-__version__ = '1.3.5'
+__version__ = '1.3.6'
 __author__ = 'debugtalk'
 __author_email__ = 'mail@debugtalk.com'
 __license__ = 'MIT'
diff --git a/httprunner/client.py b/httprunner/client.py
index 4d7ff73c..e7e72bb8 100644
--- a/httprunner/client.py
+++ b/httprunner/client.py
@@ -6,7 +6,6 @@ import time
 import requests
 import urllib3
 from httprunner import logger
-from httprunner.compat import str
 from httprunner.exception import ParamsError
 from requests import Request, Response
 from requests.exceptions import (InvalidSchema, InvalidURL, MissingSchema,
@@ -116,14 +115,11 @@ class HttpSession(requests.Session):
         self.meta_data["request_body"] = response.request.body
         self.meta_data["status_code"] = response.status_code
         self.meta_data["response_headers"] = response.headers
-
-        self.meta_data["response_body"] = response.text
-        if isinstance(self.meta_data["response_body"], str):
-            self.meta_data["response_body"] = self.meta_data["response_body"].encode("utf-8")
+        self.meta_data["response_content"] = response.content
 
         logger.log_debug("response status_code: {}".format(self.meta_data["status_code"]))
         logger.log_debug("response headers: {}".format(self.meta_data["response_headers"]))
-        logger.log_debug("response body: {}".format(self.meta_data["response_body"]))
+        logger.log_debug("response content: {}".format(self.meta_data["response_content"]))
 
         # get the length of the content, but if the argument stream is set to True, we take
         # the size from the content-length header, in order to not trigger fetching of the body
diff --git a/httprunner/report.py b/httprunner/report.py
index cadb1ba0..870ad5ab 100644
--- a/httprunner/report.py
+++ b/httprunner/report.py
@@ -9,6 +9,7 @@ from datetime import datetime
 
 from httprunner import logger
 from httprunner.__about__ import __version__
+from httprunner.compat import basestring, bytes, numeric_types
 from jinja2 import Template
 from requests.structures import CaseInsensitiveDict
 
@@ -61,6 +62,9 @@ def make_json_serializable(raw_json):
             value = value.decode("utf-8")
         elif isinstance(value, CaseInsensitiveDict):
             value = dict(value)
+        elif not isinstance(value, (basestring, numeric_types)):
+            # class instance, e.g. MultipartEncoder()
+            value = repr(value)
 
         serializable_json[key] = value
 
@@ -148,9 +152,6 @@ class HtmlTestResult(unittest.TextTestResult):
         else:
             logger.log_info("render with html report template: {}".format(html_report_template))
 
-        with open(html_report_template, "r") as fp:
-            template_content = fp.read()
-
         summary = self.summary
         logger.log_info("Start to render Html report ...")
         logger.log_debug("render data: {}".format(summary))
@@ -168,10 +169,12 @@ class HtmlTestResult(unittest.TextTestResult):
         if not os.path.isdir(report_dir_path):
             os.makedirs(report_dir_path)
 
-        report_path = os.path.join(report_dir_path, html_report_name)
-        with io.open(report_path, 'w', encoding='utf-8') as fp:
-            rendered_content = Template(template_content).render(summary)
-            fp.write(rendered_content)
+        with io.open(html_report_template, "r", encoding='utf-8') as fp_r:
+            template_content = fp_r.read()
+            report_path = os.path.join(report_dir_path, html_report_name)
+            with io.open(report_path, 'w', encoding='utf-8') as fp_w:
+                rendered_content = Template(template_content).render(summary)
+                fp_w.write(rendered_content)
 
         logger.log_info("Generated Html report: {}".format(report_path))