为了满足服务请求者对Web服务的非功能性属性的请求,就需要一种能够对非功能属性进行量化的方法对其进行量化,并做为选择服务的依据。然而这种服务的非功能性描述具有正、负两个方面的属性,本文给出一种对服务QoS量化计算的方法,并对该方法的性能进行了研究,从而为解决基于QoS约束的Web服务发现问题提出了一种有效的方法。 In order to satisfy the request of the service requester for the non-functional attributes of Web services, a method that can quantify the non-functional attributes needs to be quantified and used as the basis for selecting a service. However, the non-functional description of this service has positive and negative attributes. In this paper, a method of QoS quantification for service QoS is given and the performance of the method is studied. In order to solve this problem, Service discovery problem presents an effective method.