As a newly distributed computing paradigm under the loose coupling Internet environment, Web service provides a new technology for B2B dynamic e-business across different organizations. Some conceptions about Web service composition are defined and some properties are analyzed from the architecture perspective. A Web service composition model based on software architecture life cycle, i.e. ALBC4WS model, is proposed. which integrates the merits of existing composition strategies and is built on the basis of service publish management algorithm and service automatic inquiry-and-resume management for composition algorithm. Therefore, this model provides a dynamic and manageable underlying framework for service composition. The application results in the process of the development of OPEN-WEB prototype system show that the ALBC4WS model effectively increases the composition capability of service component and provides the robustness and self-adaptability of service composition-based application, while it also provides a dynamic management mechanism for service automatic composition.