Multimedia cloud is an emerging computing paradigm that can effectively process multimedia applications and provide multi-QoS provisions for customers. Two major challenges exist in multimedia cloud: the resource cost and the service response time. In this paper, the authors employ the proposed queuing model to optimize the resource allocation for multimedia cloud in priority service scheme. Specifically, they formulate and solve the resource cost minimization problem and the service response time minimization problem respectively. The simulation results demonstrate that the proposed optimal resource allocation method can greatly enhance the performance of multimedia cloud data center in terms of resource cost and service response time.