The application of Web Service in the client management module of telecommunications business management system Abstract With the increasing of severity of the market competition, generally declining profits, customer management for telecommunications enterprises have to provide our customers with a multi-level, individuality, and the diversification of services. For the needs of the market, in the client management module of telecommunications business management system integrated can be applied to Web Service data for customers warning level management to enhance the rate and get more profit growth. The system let the customer management module based on the functional point of J2EE APIs to create services and the performance of logic, through SOAP and UDDI this message passing accessing XML documents, and the XML document for the operation. In the process, the function of these modules interface documentation to enable it to prepare a standardized WSDL became the focus of the design. In addition, the system architecture of the model is also very important component. Using Web Service eased the pressure on the server, and greatly improved the system's efficiency and coupling. The system has been used in Hunan Telecom integrated operations management system and its surrounding systems, stability, security, fast.