An analysis is done on the requirements for information resource exchange, integration, share and interop-erability in urban application. More analysis on the development trends of Web service technologies and applicationservice models are made. Then the concept and models of Digital City application services are discussed. Furthermore, the concept, model and architecture of Digital City Application Service Platform are put forward. These mod-els and architectural designing have been applying to the Project of Beijing Information Resource Network Center anda key technological framework has been implemented accordingly.