As service-oriented architecture matures and more Web services become available, developers must test an ever-increasing volume of services. In the meantime, SOA advocates run-time system integration of loosely coupled services across heterogeneous platforms in a distributed environment and also improves the flexibility of system development. However, trustworthiness becomes a serious problem and corresponding techniques have to be brought to the table. This challenging topic constitutes the majority of my research content during my three and a half years of PhD studies. This book comes from my PhD dissertation. In this book, I introduced an effective verification framework that can greatly reduce the effort for the rapid testing and dynamic verification of SOA applications and Web Services. This verification framework consists of two key components: a underlying testing mechanism to support the static testing of services, and a policy-based dynamic verification mechanism to guard the service collaboration and composition on the fly.