Nowadays, SOA is considered as a promising architecture for enterprise applications integration. OWL-S, as a Semantic Web Service technology, promises to facilitate various service tasks, such as service specification, discovery, composition, etc.. It is essential to analysis the OWL-S process model for the quality issue of the composition of web services before its deployment. In this work, By CSPm and FDR tool, a formal analysis method for OWL-S process model, especially the interplay between the control part and dataflow part, is proposed, and its validity is illustrated by the extended version of the BravoAir process model.