Current software has more flexibility and generality in the design for the distributed application, unfortunately, which gives rise to some efficiency problems in the implementation. In order to improve the performance of Web services, this paper introduces partial evaluation into distributed environments. Partial evaluation specializes generic programs into specific realization. We propose the partial evaluation for object-oriented programs and implement the distributed partial evaluation based on the specialization of Java Byte Code. The experiment results show that partial evaluation is effective to optimize Web services. The integration of partial evaluation with Web services facilitates programs more generality and scalability.