With the development of the third generation mobile communication system, 3GPP proposes the conception of VHE (Virtual Home Environment) in UMTS system, which aims to realize the portability of PSE (Personal Service Environment) when user spanning the boundary of the network and terminal, namely, the VHE ensures that user is consistently presented with the same personalized features, User Interface customization and services in whatever terminal and whatever network (within the capabilities of the terminal and network), wherever the user may be located. As one of service provision modes in 3G/B3G, many international organizations for standardization and research institutions study the VHE, and present some feasible solutions and technologies, such as CAMEL, MExE and SAT. However, these technologies only can realize partial functions of VHE in some degree, and can't meet the need of future service development.Comparing with former simplex network and terminal, VHE service provision must consider multidimensional information including the characteristics of multifarious heterogeneous networks, the capabilities of different terminals and personalized user preferences, apperceive the changes of network and terminal's context information, and proceed service content negotiation and adaptation automatically, so as to provide user the optimal service experience when user spans network boundary and replaces terminal. However, as one of the key problems in VHE system, service adaptation mechanism is still lacking feasible solutions.On the base of existing researches, this paper analyzes the requirements for service in VHE system, emphasizes particularly on the service discovery, the realization framework of service context negotiation and content adaptation, and correlative mechanism and algorithm of service adaptation during the value-added service provision in VHE. Aiming at the problem of service discovery, selection and usage in VHE system, by the design of value-added service provision architecture on network side and user terminal management platform on terminal side, an effective service discovery and access mode is presented, as