Systems have moved away from the close, familiargroup and relativestatic pattern to the open, publicvisiting and dynamic coordinate pattern. Because of the unfamiliar feature between different entities, it is important to use a trustguarantee mechanism. In this paper, we clearly discuss the challenges for service composition from the trust point of view, including the basic concepts, the key techniques and the related work such as selecting trustworthy services, runtime guarantee mechanism, security, trust evaluation, etc. After that, a comparative study among some key techniques is presented. Finally, some open issues are discussed, and the future direction of trustworthy service composition is pointed out.