climate change should have to be considered as one of the fundamental problems in-volved with the fish conservation in yangtze river.in recent 50 years,the temperature of the yangtze river basin gradually raised,at a rate of 0.197℃/10year at yichang section.meantime,the inflow decreased year by year,especially in spring and winter season,while the rainfall concentrated into summer.these joint factors degraded the aquatic environment stability,such as the great fluctuating of precipitation and inflowing annually and monthly,foundational water temperature getting warmer,as well as high risks of both drought and flood,etc.several huge hydropower stations,such as three gorges,Xiluodu and Xiangjia-ba,stand along the yangtze river,their operation might aggravate the hydraulic and temperature effects.after impounding process of Xiangjiaba and Xiluodu,the reservoir water body thermally stratified and the discharging water temperature dropped in spring and raised in autumn.for three gorges reservoir,only short and weak stratification can be found in late april,but the hysteresis effects of the 660 km length reservoir deferred one month during the temperature raising phase in spring water and descending in au-tumn in yichang section.these phenomena had negative effects on natural populations of rare,endemic and economic fish resources,for instance,the spawning field modification and breeding scale down of chinese sturgeon and four asian carps,suitable habitat deterioration of endemic fishes,even posing threats to the survival of some endangered species.the conservation countermeasures should be implemented timely,in-cluding ecological operation,layered water intake structures,basin-wide monitoring system,and artificial germplasm preservation.