"Digital Province" is the basic unit for the national informatization in China.To maximize the benefits of information application infrastructure and to break the "barrier" between different departments or regions, this paper put forward a theoretical framework of "information application infrastructure" based on the practice of Fujian provincal informatization project, i.e."Digital Fujian".Targeting to the key issues of information resources development, sharing, application and service, and aiming at improving the level of information engineering and information services, this framework should be centered on some public supporting software and a specialized information service institution, which act as a information broker bridging the information provider and consumer.We designed a low-costing, intensive and sustainable information sharing and service technical system and introduced the components of public service software platforms for informatization application, including supporting platform for general information security, e-government application, e-business application, enterprise informatization application, community informatization application and geospatial information application etc.Digital regional information application infrastructure is the upper infrastructure of information network, information security and information resources and is to establish sustainable information resources and technical service chain between the information provider and consumer.Meanwhile, it provided fundamental, public application service support for various digital regional informatization application projects, such as e-government, e-commerce, digital city, digital community or location services, and it also provided the theoretical and practical basis for fundamentally achieving the utilizing, sharing and application service of information resources.