Focus on the spawning grounds of Coreius guichenoti in the segment of water reduced in Jinping river bend, based on the spawning suitability and characteristic section of spawning grounds,this paper discusses the change of hydrological regime caused by the operation of Jinping hydropower stage I and II , analyzes the influence on fish spawning, obtains that the minimum ecological basic flow is 298 m3/s and optimizes the hydropower station regulation scheme.