diff --git a/LICENSE b/LICENSE
new file mode 100644
index 0000000..e4d1506
--- /dev/null
+++ b/LICENSE
@@ -0,0 +1,20 @@
+The MIT License (MIT)
+
+Copyright (c) 2017 zhangpanyi
+
+Permission is hereby granted, free of charge, to any person obtaining a copy of
+this software and associated documentation files (the "Software"), to deal in
+the Software without restriction, including without limitation the rights to
+use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of
+the Software, and to permit persons to whom the Software is furnished to do so,
+subject to the following conditions:
+
+The above copyright notice and this permission notice shall be included in all
+copies or substantial portions of the Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS
+FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR
+COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER
+IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
+CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
\ No newline at end of file
diff --git a/astar/blockallocator.cpp b/astar/blockallocator.cpp
index 5848fbb..c43fed6 100644
--- a/astar/blockallocator.cpp
+++ b/astar/blockallocator.cpp
@@ -196,4 +196,4 @@ void BlockAllocator::clear()
     num_chunk_count_ = 0;
     memset(chunks_, 0, num_chunk_space_ * sizeof(Chunk));
     memset(free_lists_, 0, sizeof(free_lists_));
-}
\ No newline at end of file
+}
diff --git a/astar/blockallocator.h b/astar/blockallocator.h
index 80910d6..c16a1a0 100644
--- a/astar/blockallocator.h
+++ b/astar/blockallocator.h
@@ -1,4 +1,22 @@
-#ifndef __BLOCKALLOCATOR_H__
+/*
+* Copyright (c) 2006-2009 Erin Catto http://www.box2d.org
+*
+* This software is provided 'as-is', without any express or implied
+* warranty.  In no event will the authors be held liable for any damages
+* arising from the use of this software.
+* Permission is granted to anyone to use this software for any purpose,
+* including commercial applications, and to alter it and redistribute it
+* freely, subject to the following restrictions:
+* 1. The origin of this software must not be misrepresented; you must not
+* claim that you wrote the original software. If you use this software
+* in a product, an acknowledgment in the product documentation would be
+* appreciated but is not required.
+* 2. Altered source versions must be plainly marked as such, and must not be
+* misrepresented as being the original software.
+* 3. This notice may not be removed or altered from any source distribution.
+*/
+
+#ifndef __BLOCKALLOCATOR_H__
 #define __BLOCKALLOCATOR_H__
 
 #include <cstdint>
@@ -32,4 +50,4 @@ class BlockAllocator
     static bool     s_block_size_lookup_initialized_;
 };
 
-#endif
\ No newline at end of file
+#endif