Because of the heterogeneity, complexity, and autonomy of wide spread Grid resources, the assurance of the end-to-end Grid QoS becomes a challenge. The G-RSVPMproposed in this paper is a Grid resource reservation model. Mobile agents are used to implement the model to achieve not only the network resource reservations but also the computing resource reservations for Grid applications. The performance simulation environment of G-RSVPM under RSVP/ns on linux is designed and implemented. The simulation result shows that the model can flexibly adapt to the changinge environment and achieve better end-to-end QoS assurance both of computing resources and network resources in Grid than the traditional way.