Abstract: A significant change in the number of connections can invalidate the parameter settings of BLUE and cause the queue backlog oscillation between loss and under utilization Analysis and experiments show that BLUE is not strong enough to adapt to dynamic network environment To solve this problem, an improved method is proposed though adopting the adaptive thought The main idea of it is to adjust adaptively the marking probability of BLUE according to the arriving rate of packets Extensive simulation experiments show that the proposed method can enhance the robustness of BLUE considerably under dynamic network environment Compared with BLUE, it can improve link utilization and decrease packet loss rate at the same time