Abstract: OSA/Parlay API is the specification of opening telecommunication services interfaces of Next-Generation-Network. At the distributed network architecture of OSA, how to provide the open services capability of OSA/Parlay to the third party application is a crucial technical issue. The internal relationship between OSA/Parlay and Web Service is discovered by studying the publish、discovery and binding mechanisms of OSA/Parlay Web Service. The process and feature of the mechanisms of Parlay X Web Service are also analyzed .An SMS example based on Parlay X Web Service is given.