Abstract: Model checking techniques can be effectively applied to the verification of exceptions in Web services composition, such as feature interaction problems, but the verification process is not fully automatic. In order to improve the verification of intelligence level, we need to transform 13PEI_ language into the input language of MCTK, a symbolic model checker developed by us. Based on detailed research on the BPEL control flow, we proposed a formal model for activities implementation and gave the semantics of the BPEL activities implementation. We then respectively developed an algorithm for automatically converting the BPEI_ process to seven-tuple collections and an algorithm for converting those seven-tuples to input language of MCTK，such seven-tuples included effective information about state changes in the business implementation process. I}hc results show that the proposed algorithm can effectively verify feature interarction in Web Services,and support the verification of epistemic logic.

Key words: Model checking, Web service composition, Feature interaction, BPEL