Abstract: The congestion control mechanisms used in Internet have been the focus of numerous studies and have undergone a number of enhancements. However, even with these enhancements, TCP connections still experience alarmingly high loss rates, especially during times of congestion. The IETF has addressed this problem by advocating the deployment of active queue management mechanisms, such as RED, in the network, But RED have some problems, for example the average queue length changing slowly when congestion starting and ending. To alleviate this problem, a Dynamic-Weight RED(DWRED) is proposed which can quickly be conscious of the congestion and dynamic adjust the weight. DWRED use the average queue length to estimate the change of the queue and adjust the weight to alleviate the congestion and drop when the congestion is over. The time of congestion is shorter than the RED. The result is proved by the simulation.