Abstract: In this paper, the interaction mode required for the interoperation between distributed and heterogeneous workflow management system are analyzed first.Then a web service based solution for supporting the integration and interoperation of heterogeneous workflow management system is proposed. Web service is widely accepted for its openness and standardization. It has become a new paradigm for Internet based distributed applications. Various aspects in web service based integration and interoperation of heterogeneous workflow management system, such as information integration between heterogeneous workflow management systems, implementation of the call semantics between workflow engines, and description, publishing, and binding of workflow enactment service, are discussed in this paper.