Abstract:As the amount of Web services over the Internet grows continuously,these services can be interconnected to form a service overlay network(SON).On the basis of SON,building value-added services by service composition is an effective method to satisfy the changeable functional and non-functional QoS (quality of service) requirements of customers.However,the previous research on QoS-aware service composition in SON mainly focuses on the context where services have simple interactions,and it can not support application scenarios with complex business collaboration in electronic commerce.This paper proposes the HOSS(hierachical service composition framework based on Service overlay networks) scheme based on active service overlay network (ASON) which is a kind of programmable SON.HOSS can be used to construct more general-purpose SON through describing the relations among services using business protocols.In HOSS,business protocols instead of interactive messages are adopted to simplify the description of service composition requirements and are mapped to dynamical user perspective of SON to implement service composition on demand.