In recent years, there are more and more Web services with different qualities available for users to choose from. In order to find the best service from the massive candidates, it is necessary to provide a query mechanism for users to search by QoS(Quality of service). However, the existing Web services management models are mostly based on functional attributes, lacking of quality constraints. And although there have been some QoS management models, they have many disadvantages, and their query performance is relatively poor. Therefore, we propose a new QoS-based Web services management model to manage and navigate Web services. Considering that multi-dimensional data model is useful in managing relational data and it provides OLAP operations to navigate data conveniently, we adopt this technology in the modeling approaches, and name the model as MQM(Multi-dimensional QoS Model). It has been proved that MQM is effective and efficient, and it enables users to retrieve the needed services more accurately and faster by some experiments.