As composite web services are often long lasting, loosely coupled, cross application and administrative boundaries, transactional support to integrated business via composing individual web services is a critical issue. Currently, WS-BPEL which is more expressive than traditional workflow language, has been the de facto standard for web service composition. However, most works on transactional properties focus on structured workflows, and there is no tool to validate transactional properties for WS-BPEL processes. In this paper, we present a technique to analyze WS-BPEL files to validate whether a process complies with the expected transactional properties. We identify key point and risk point to help validate whether a process is well-formed. The validation technique can assess the correctness of WS-BPEL process specifications and therefore can help process designers to identify ill-formed processes.