Abstract: As one kind of middleware technology put forward recently, application platform is intended to provide more powerful support for applications, e. g., improve quality, enable reuse, increase productivity, lower maintenance, etc. The Software Architecture, a new discipline emerging in recent years, has laid a necessary foundation for the research and development of application platforms. CASE integrating tools and environment are the physical supports for application platforms, while the repository of frameworks and OO organization are the guarantees for integrating an application platform.Application platform is not only an emerging new concept and technology but also of practical significance and has the broadest application prospect. In this paper, the application platform and its key supporting and relating technology （i. e., the concept of application platform itself, the software architecture discipline, the repository style and the new framework concept） are surveyed. The authors’ perspective is also presented.