SOA (Service-oriented architecture) is developed from original distributed computation based on component. Its purpose is to pursue agility, which separates business logic from the specific technology, and thus the application constructed by SOA can adapt to business & technology evolving and can facilitate software reuse and system integration as well. SOA is a methodology of design, its purpose is to furthest reuse application-neutral services to increase IT adaptability and efficiency. It shields the difference among platforms, programming languages, operating systems and hardware architecture, and achieves a simple integration of applications. Today we are faced with systems equipped with distributed software, application integration, different platforms, various agreements and equipments. SOA can be used to eliminate problems resulted form various agreements and platforms, to gain a seamless integration of applications. The usage of SOA was accelerated after the emergence of standards-based integration technologies (such as Web services and XML). The advantages of SOA are the highly reusability, agility, excellent expansibility and availability. This thesis firstly elaborated on SOA related concept, features, advantages, and the main techniques. An application meta-model of SOA was proposed and integration strategy of application system based on SOA was also brought forward. Secondly, analyzed the advantage of using the techniques of J2EE to design SOA, and a SOA framework was designed. And then in the light of a specific project, a SOA-based developing platform was designed and implemented, the background of the platform, the process of the improving developing, as well as the core component of the platform-- service engine, entity engine, workflow engine were introduced in detail. For showing the developing process of the platform, the model of archivesAccept was given, either. Finally, the paper was summed up and the future work of the platform was explored.