diff --git a/taskflow/tests/unit/patterns/test_unordered_flow.py b/taskflow/tests/unit/patterns/test_unordered_flow.py
new file mode 100644
index 00000000..1108d971
--- /dev/null
+++ b/taskflow/tests/unit/patterns/test_unordered_flow.py
@@ -0,0 +1,109 @@
+# -*- coding: utf-8 -*-
+
+#    Copyright (C) 2014 Yahoo! Inc. All Rights Reserved.
+#
+#    Licensed under the Apache License, Version 2.0 (the "License"); you may
+#    not use this file except in compliance with the License. You may obtain
+#    a copy of the License at
+#
+#         http://www.apache.org/licenses/LICENSE-2.0
+#
+#    Unless required by applicable law or agreed to in writing, software
+#    distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
+#    WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
+#    License for the specific language governing permissions and limitations
+#    under the License.
+
+from taskflow import exceptions as exc
+from taskflow.patterns import unordered_flow as uf
+from taskflow import retry
+
+from taskflow import test
+from taskflow.tests import utils
+
+
+def _task(name, provides=None, requires=None):
+    return utils.ProvidesRequiresTask(name, provides, requires)
+
+
+class UnorderedFlowTest(test.TestCase):
+
+    def test_unordered_flow_starts_as_empty(self):
+        f = uf.Flow('test')
+
+        self.assertEqual(len(f), 0)
+        self.assertEqual(list(f), [])
+        self.assertEqual(list(f.iter_links()), [])
+
+        self.assertEqual(f.requires, set())
+        self.assertEqual(f.provides, set())
+
+        expected = 'taskflow.patterns.unordered_flow.Flow: test; 0'
+        self.assertEqual(str(f), expected)
+
+    def test_unordered_flow_add_nothing(self):
+        f = uf.Flow('test')
+        result = f.add()
+        self.assertIs(f, result)
+        self.assertEqual(len(f), 0)
+
+    def test_unordered_flow_one_task(self):
+        f = uf.Flow('test')
+        task = _task(name='task1', requires=['a', 'b'], provides=['c', 'd'])
+        result = f.add(task)
+
+        self.assertIs(f, result)
+
+        self.assertEqual(len(f), 1)
+        self.assertEqual(list(f), [task])
+        self.assertEqual(list(f.iter_links()), [])
+        self.assertEqual(f.requires, set(['a', 'b']))
+        self.assertEqual(f.provides, set(['c', 'd']))
+
+    def test_unordered_flow_two_independent_tasks(self):
+        task1 = _task(name='task1')
+        task2 = _task(name='task2')
+        f = uf.Flow('test').add(task1, task2)
+
+        self.assertEqual(len(f), 2)
+        self.assertEqual(set(f), set([task1, task2]))
+        self.assertEqual(list(f.iter_links()), [])
+
+    def test_unordered_flow_two_dependent_tasks(self):
+        task1 = _task(name='task1', provides=['a'])
+        task2 = _task(name='task2', requires=['a'])
+        f = uf.Flow('test')
+        self.assertRaises(exc.InvariantViolation, f.add, task1, task2)
+
+    def test_unordered_flow_two_dependent_tasks_two_different_calls(self):
+        task1 = _task(name='task1', provides=['a'])
+        task2 = _task(name='task2', requires=['a'])
+        f = uf.Flow('test').add(task1)
+        self.assertRaises(exc.InvariantViolation, f.add, task2)
+
+    def test_unordered_flow_two_dependent_tasks_reverse_order(self):
+        task1 = _task(name='task1', provides=['a'])
+        task2 = _task(name='task2', requires=['a'])
+        f = uf.Flow('test')
+        self.assertRaises(exc.InvariantViolation, f.add, task2, task1)
+
+    def test_unordered_flow_two_dependent_tasks_reverse_order2(self):
+        task1 = _task(name='task1', provides=['a'])
+        task2 = _task(name='task2', requires=['a'])
+        f = uf.Flow('test').add(task2)
+        self.assertRaises(exc.InvariantViolation, f.add, task1)
+
+    def test_unordered_flow_two_task_same_provide(self):
+        task1 = _task(name='task1', provides=['a', 'b'])
+        task2 = _task(name='task2', provides=['a', 'c'])
+        f = uf.Flow('test')
+        self.assertRaises(exc.DependencyFailure, f.add, task2, task1)
+
+    def test_unordered_flow_with_retry(self):
+        ret = retry.AlwaysRevert(requires=['a'], provides=['b'])
+        f = uf.Flow('test', ret)
+        self.assertIs(f.retry, ret)
+        self.assertEqual(ret.name, 'test_retry')
+
+        self.assertEqual(f.requires, set(['a']))
+        self.assertEqual(f.provides, set(['b']))