Existing power and rate control methods for wireless communication networks aim to maximize the system capacity and the network throughput, and attempt to increase the quality-of-service (QoS), but cannot guarantee the QoS. This paper presents a new power and rate control method for wireless communication networks, which is based on the priority of QoS, so the QoS can be guaranteed. A dual closed-loop power and rate controller is designed. The transmission rate is controlled by the outer loop, the target transmission rate is obtained (thus the optimal target signal-to-inference ratio (SIR) can relatively be determined) based on the priority of QoS. According to the target SIR, the transmit power is controlled by the inner loop to make the actual SIR track the target one. Simulation results show that the proposed power and rate control method has good control performance.