中文摘要：

针对SOA实施过程中Web服务协商的需要，提出了一种Web服务协商协议．定义了通信原语，在服务提供者和服务消费者之间动态地协商服务信息，并采用Pe讲网模型对该协议进行了形式化描述，对Web服务组合进行建模及元素映射，给出了Petri网模型生成算法．

英文摘要：

In order to meet Web service negotiation requirements in SOA （Service- Oriented Architecture）, a service negotiation protocol is proposed to negotiate automatically quality of service budgets between possible service provider and service consumer. A Petri nets model is used to describe formally negotiation protocol. Based on Petri net theory, the forreal definition and graphic description were proposed for web services and their composition; the dement mapping process was also illustrated. Then an algorithm was proposed to construct the Petri net model for web services negotiation composition.