Abstract: With the increase of Internet size, maintaining its necessary QoS（quality of service） is the forefront of network performance research. Summarized in this paper are all kinds of improved methods of RED algorithm in the past ten years. At the same time, some analyses are made of RED performance derived from random queue model and an improvement is made in maintaining fair bandwidth in all types of flows of links, resulting in New RED queue management mechanism. Finally, a comparison is made between RED mechanism and New RED mechanism by using NS. The result of simulation verifies that New RED queue management mechanism effectively maintains fair bandwidth in all types flows of links. So this mechanism doesn’t drop many packets of flows which have congestion control in the bottleneck links （for instance FTP flows）.