Abstract: An algorithm based on the delay detection mechanism is proposed， which estimates the state of congestion by monitoring the packet queueing delay in the bottleneck gateway and sets a detection threshold. Once the queueing delay of a packet exceeds the threshold, the packet will be marked according to the mechanism of explicit congestion notification (ECN) to notify the transport control protocol (TCP) source. In order to be self-adaptive and easier to perform in the gateway, the algorithm evaluates the weight of different TCP flows according to their occupancy of the gateway resources in every cycle and chooses the measurements of several TCP flows whose weights are the heaviest to update the congestion detection threshold. Through the algorithm, the gateway is not only capable of achieving high throughput, high link utilization and stable mean queue length, but also able to allocate resources more fairly for bursty traffic. The simulation result on network simulator version 2(ns-2) shows that the algorithm can achieve desired performance.