The coordination between agent service and Web service is the key factor for intelligent Web service management in the multi-agent based Web service framework. In view of the drawbacks of existing coordination approaches for agent service and Web service, this paper proposed a multi-agent and workflow-based Web service management model. Through analyzing the interaction relations between agent service and Web service in the logical action-based task environment, a uniform task view for intelligent Web service is built. And based on such task view, a workflow towards special task is designed to realize intelligent Web service discovery and cooperation and composition. This model provides a more flexible Web service management.