Web Service Negotiation is a technology that autonomous entities reach agreement and meet both needs through negotiation. Web Service negotiation mechanism and coordinated-negotiation architecture on this basis have become hot issues of current research. The Coordinated-Negotiation Architecture of Web Service Composition based on Agent is a relative popular one in current architectures. However, there are some problems of it: unreasonable use of time and data link resources in the condition of multi-negotiation concurrency, which results in inefficiency of negotiation; lack of effective processing when confronting negotiation failure. In this paper, we put forward applying asynchronous communication theory to the process of Web Service Negotiation and extend effective processing when confronting negotiation failure in the process of Web Service Negotiation, present a new Web Service Negotiation Mechanism and a new Web Service Composition Coordinated-Negotiation Architecture on this basis so as to solve the problems above.