Abstract:Patitionbased reasoning(PBR) is a method of reasoning with partitions of related logical axioms. A new method of web service composition based on MP algorithm is proposed for improving the composition of web services that is located in different UDDIs,and the performance of the semantic reasoner in the process of web service composition.Thus the new method proves more efficient than the one based on traditional theorem proving.A method of extracting the process model from proof based on the idea of πcalculus is also introduced.To make use of the subtype relation provided by semantic reasoner,a new process to handle this process is defined systematically.