Cloud computing becomes a popular trend in recent years. In the meanwhile, content delivery network has been used for many years to distribute content all over the world. The relation between cloud computing and content delivery network is very interesting. In this paper, we proposed a cloud based content delivery network. This architecture integrates cloud infrastructure and content delivery network system together. It provides a low cost and elastic web serving cloud platform. Besides, it also provides easy way to manage data for web content developers, and accelerate the speed for users to access web sites. This system uses Hadoop Distributed File System as a cloud infrastructure service, and creates many data clusters around the world. Therefore, content providers could place content to closest node from end users. The result shows a high performance and flexible solution to build a personal content delivery network over cloud.