Adaptive and reconfigurable service provisioning is a promising research direction for NGN service technologies. It will lay the foundation of a converged network environment, in which users can feel free to enjoy various advanced services. In this paper we propose a new Adaptive Service Provisioning Architecture(ASPA) applicable to NGN. The architecture is composed of five subsystems enriching the current NGN service provisioning with novel capability of adaptation to user environment, network environment and service environment. Detailed modular structure of each subsystem is presented with emphasis on the description of adaptation capabilities. Finally an application example is provided to illustrate the rational of ASPA.