We suggest a new minimum credit method for the dynamic bandwidth allocation in EPON. In the suggested method, to eliminate the unused transmission time-slot, each ONU requests no more than a predetermined maximum. We analyze the upstream channel resource wastage when traffic is light. Based on the analysis, we derive a minimum credit that eliminate the upstream channel resource wastage. The OLT estimates a traffic load and grants a minimum credit when the request is smaller than the minimum credit and traffic is light. Using simulation, we show the minimum credit discipline is superior than the existing methods in the mean delay and the frame loss rate.