diff --git a/README.md b/README.md
index 4734f20..987d2ab 100644
--- a/README.md
+++ b/README.md
@@ -63,17 +63,38 @@ Then, please create the events like this. This will send the event to fluent, wi
 ### Python logging.Handler interface
 
 This client-library also has FluentHandler class for Python logging module.
+Custom default entries or [LogRecord attributes](https://docs.python.org/2/library/logging.html#logrecord-attributes) can be used when creating FORMAT dictionary.
 
     import logging
+    import socket
     from fluent import handler
-    
+
+    FORMAT = {
+        'host': socket.gethostname(),
+        'error_line': '%(lineno)d',
+        'error_file': '%(filename)s',
+        'code': '%(levelno)s',
+        'type': '%(levelname)s',
+        'logger': '%(name)s',
+        'module': '%(module)s',
+        'function_name': '%(funcName)s',
+        'stack_trace': '%(exc_text)s'
+    }
+
+    formatter = handler.FluentRecordFormatter(FORMAT)
+    fluent_handler = handler.FluentHandler('app.follow', host='host', port=24224)
+    fluent_handler.setFormatter(formatter)
+
     logging.basicConfig(level=logging.INFO)
     l = logging.getLogger('fluent.test')
-    l.addHandler(handler.FluentHandler('app.follow', host='host', port=24224))
+    l.addHandler(fluent_handler)
+
+    l.info("This log entry will be logged with key: 'message'.")
     l.info({
       'from': 'userA',
       'to': 'userB'
     })
+    l.info('{"from": "userC", "to": "userD"}')
 
 ## Testing
 
diff --git a/fluent/handler.py b/fluent/handler.py
index e14c036..c68314d 100644
--- a/fluent/handler.py
+++ b/fluent/handler.py
@@ -16,35 +16,33 @@
 from fluent import sender
 
 
-class FluentRecordFormatter(object):
-    def __init__(self):
-        self.hostname = socket.gethostname()
+class FluentRecordFormatter(logging.Formatter):
+    def __init__(self, fmt=None, datefmt=None):
+        super(FluentRecordFormatter, self).__init__(fmt, datefmt)
+        if isinstance(fmt, dict):
+            pass
+        elif isinstance(fmt, str):
+            try:
+                self._fmt = json.loads(str(fmt))
+            except ValueError:
+                self._fmt = self.default_format()
+        else:
+            self._fmt = self.default_format()
 
     def format(self, record):
-        data = {'sys_host': self.hostname,
-                'sys_name': record.name,
-                'sys_module': record.module,
-                # 'sys_lineno': record.lineno,
-                # 'sys_levelno': record.levelno,
-                # 'sys_levelname': record.levelname,
-                # 'sys_filename': record.filename,
-                # 'sys_funcname': record.funcName,
-                # 'sys_exc_info': record.exc_info,
-                }
-        # if 'sys_exc_info' in data and data['sys_exc_info']:
-        #    data['sys_exc_info'] = self.formatException(data['sys_exc_info'])
-
+        self.format_data(record)
+        data = dict([(key, value % record.__dict__) for key, value in self._fmt.items()])
         self._structuring(data, record.msg)
         return data
 
     def _structuring(self, data, msg):
         if isinstance(msg, dict):
             self._add_dic(data, msg)
-        elif isinstance(msg, str):
+        elif isinstance(msg, basestring):
             try:
                 self._add_dic(data, json.loads(str(msg)))
             except ValueError:
-                pass
+                self._add_dic(data, {'message': msg})
 
     @staticmethod
     def _add_dic(data, dic):
@@ -52,6 +50,28 @@ def _add_dic(data, dic):
             if isinstance(key, basestring):
                 data[str(key)] = value
 
+    def format_data(self, record):
+        record.message = record.getMessage()
+        if self.usesTime():
+            record.asctime = self.formatTime(record, self.datefmt)
+        if record.exc_info:
+            # Cache the traceback text to avoid converting it multiple times
+            # (it's constant anyway)
+            if not record.exc_text:
+                record.exc_text = self.formatException(record.exc_info)
+
+    def usesTime(self):
+        for _, value in self._fmt.items():
+            if value.find('%(asctime)') >= 0:
+                return True
+        return False
+
+    def default_format(self):
+        return {
+            'sys_host': socket.gethostname(),
+            'sys_name': '%(name)s',
+            'sys_module': '%(module)s'
+        }
 
 class FluentHandler(logging.Handler):
     '''
diff --git a/tests/test_handler.py b/tests/test_handler.py
index 7f944a8..182917e 100644
--- a/tests/test_handler.py
+++ b/tests/test_handler.py
@@ -27,20 +27,27 @@ def test_simple(self):
 
         logging.basicConfig(level=logging.INFO)
         log = logging.getLogger('fluent.test')
-        handler.setFormatter(fluent.handler.FluentRecordFormatter())
+        formatter = fluent.handler.FluentRecordFormatter()
+        handler.setFormatter(formatter)
         log.addHandler(handler)
         log.info({
             'from': 'userA',
             'to': 'userB'
         })
+        log.info('{"from": "userC", "to": "userD"}')
+        log.info("Test log message")
         handler.close()
 
         data = self.get_data()
         eq = self.assertEqual
-        eq(1, len(data))
+        eq(3, len(data))
         eq(3, len(data[0]))
         eq('app.follow', data[0][0])
         eq('userA', data[0][2]['from'])
         eq('userB', data[0][2]['to'])
+        eq('userC', data[1][2]['from'])
+        eq('userD', data[1][2]['to'])
+        eq('Test log message', data[2][2]['message'])
+        self.assertFalse(formatter.usesTime())
         self.assertTrue(data[0][1])
         self.assertTrue(isinstance(data[0][1], int))