Verification for interaction protocol of Web services is crucial to both implementation and composition of Web services. The verification process can prove important and desirable properties of the control flow and data flow of Web services. Model checking is a promising technique for verification and validation of software systems. In this paper, we present a model checking framework to specifying and verifying Web service flow based on annotated OWL-S. By using annotation layers, an OWL-S Process model can be extended with constraints (like time properties) information. An underlying OWL-S model and one or more constraint annotation layers compose a complete specification of a Web process imposed specific constraints. By transforming the annotated OWL-S model to a TCPN (Time Constraints Petri net) model, Web service flow can be analyzed and verified. The method allows us to add conveniently constraints information to a Web process model, and state whether a process satisfies given properties without actual execution based on its specification.