ASC (Automatic Service Composition) is the key issue in cloud computing.It is an urgent problem of ASC in cloud computing to provide multiple composition service which can satisfy the personalized requirements for large-scale users.An extended graph-planning based Top-K service composition method is proposed in this paper.By using service indexes and the auxiliary nodes in extended planning graph
Top-K composition service can be found through one search.The approach can improve the efficiency of service composition and ensure the correctness of the result.It applies to the ASC problem in cloud which has a large number of services and the users' requirements are personalized.