The river ecological flow has been one of the research foci of geographical sciences in the world.Based on the field investigation,we selected the habitat simulation method which comprises the information of hydrology and biology according to the unique feature ecological environment of Yalong mainstream and the goal of protection.This can protect the habitat of aquatic living things and maintain the good ecological function of water exporting river.The result showed that the simulated ecological flow in river course of various stations during different year was near or between minimum and suitable ecological flow calculated by Tennate method.While the standard of Tennant method is based on the local living habits and climate feature,which fits the local river ecology and environmental condition.So the results calculated by habitat simulation method are feasible in calculating river ecological flow.