diff --git a/docs/CHANGELOG.md b/docs/CHANGELOG.md
index 44ce45d1..a87ecc09 100644
--- a/docs/CHANGELOG.md
+++ b/docs/CHANGELOG.md
@@ -2,6 +2,10 @@
 
 ## 3.0.5 (2020-05-21)
 
+**Added**
+
+- feat: add default header `HRUN-Request-ID` for each testcase #721
+
 **Fixed**
 
 - fix: ensure referenced testcase share the same session
diff --git a/httprunner/__init__.py b/httprunner/__init__.py
index 1c9ba758..36b1d4d9 100644
--- a/httprunner/__init__.py
+++ b/httprunner/__init__.py
@@ -1,4 +1,4 @@
-__version__ = "3.0.4"
+__version__ = "3.0.5"
 __description__ = "One-stop solution for HTTP(S) testing."
 
 from httprunner.runner import HttpRunner
diff --git a/httprunner/runner.py b/httprunner/runner.py
index 95219187..a3ab7315 100644
--- a/httprunner/runner.py
+++ b/httprunner/runner.py
@@ -1,5 +1,6 @@
 import os
 import time
+import uuid
 from datetime import datetime
 from typing import List, Dict, Text
 
@@ -31,6 +32,7 @@ class HttpRunner(object):
 
     success: bool = True  # indicate testcase execution result
     __project_meta: ProjectMeta = None
+    __hrun_request_id: Text = None
     __step_datas: List[StepData] = None
     __session: HttpSession = None
     __session_variables: VariablesMapping = {}
@@ -45,6 +47,10 @@ class HttpRunner(object):
         self.__session = session
         return self
 
+    def with_request_id(self, hrun_request_id: Text) -> "HttpRunner":
+        self.__hrun_request_id = hrun_request_id
+        return self
+
     def with_variables(self, variables: VariablesMapping) -> "HttpRunner":
         self.__session_variables = variables
         return self
@@ -60,6 +66,10 @@ class HttpRunner(object):
         parsed_request_dict = parse_data(
             request_dict, step.variables, self.__project_meta.functions
         )
+        parsed_request_dict["headers"].setdefault(
+            "HRUN-Request-ID",
+            f"{self.__hrun_request_id}-{str(int(time.time() * 1000))[-6:]}",
+        )
 
         # prepare arguments
         method = parsed_request_dict.pop("method")
@@ -131,6 +141,7 @@ class HttpRunner(object):
         case_result = (
             HttpRunner()
             .with_session(self.__session)
+            .with_request_id(self.__hrun_request_id)
             .with_variables(step_variables)
             .run_path(ref_testcase_path)
         )
@@ -183,6 +194,7 @@ class HttpRunner(object):
         parse_config(self.config)
         self.__start_at = time.time()
         self.__step_datas: List[StepData] = []
+        self.__hrun_request_id = self.__hrun_request_id or f"HRUN-{uuid.uuid4()}"
         self.__session = self.__session or HttpSession()
         self.__session_variables = {}
         for step in self.teststeps:
diff --git a/pyproject.toml b/pyproject.toml
index 6614464f..5c47f4bf 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -1,6 +1,6 @@
 [tool.poetry]
 name = "httprunner"
-version = "3.0.4"
+version = "3.0.5"
 description = "One-stop solution for HTTP(S) testing."
 license = "Apache-2.0"
 readme = "README.md"