QoS (Quality of Service) parameters play a key role in selecting Grid resources and optimizing resources usage efficiently. Although many works have focused on using QoS metrics, surprisingly few tools support the monitoring and analysis of QoS metrics of Grid services. This paper presents a novel framework which supports the monitoring and analysis of QoS metrics in the Grid. Our approach is that, firstly, we develop a classification of important QoS metrics for Grid services that should be monitored and analyzed. Secondly, sensors are developed to monitor QoS of disparate Grid services by using a peer-to-peer Grid monitoring middleware. The dependencies among Grid services are modeled. Based on that, several techniques are used to analyze QoS metrics of dependent Grid services.