EPON（Ethernet Passive Optical Network） is viewed by many as an attractive solution to the next generation access network because of its low cost and high bandwidth.And dynamic bandwidth allocation algorithm（DBA） has been an area of intense research in recent years.In this paper most of the proposed DBAs are reviewed

and we propose a new DBA for improving bandwidth utilization and packet delay.OLT sent GATEs according to the REPORT which says the size of ONU queue.If the size of ONU queue is less than the maximum transmission window the ONU was authorized priority.In the simulation

we can see this algorithm can reduce packet delay and improve bandwidth utilization.