Abstract: Water is the dominant factor of eco-geographic environment of the keriya River-According to the distribution of river system,yutian artificial oasis and other natural oases commonly form the ecosystem of the Keriya River valley.The Keriya Riveris belong to mixing suppy type of river, of Which glacial melting snow accounts for 71%. The annual runoff variation is bigger but the inter annual variation is stable and Cv=1.7. Natural replenishment of ground Water mostly comes from the conversion of surface water. Therefore, in the development and utilization of water resource, we should not only analyse the effects of establishing oases in the upper reaches on the lower reaches, but also consider the restraint effect of maintaining natura loases in the lower reaches on the development of artificial oases in upper reaches, making overall plan and taking all factors into consideration. The natural oasis, situated in the northern part and extend more tran 200 km into the Taklimakan Desert and 5-10 km in width along river terracf, river flat and scattered flow area, provides a forefront defence for the Yutian oases. It has importantly social and ecologic significance. At present vegetation hasdeclined due to the changes of river system and flood retreat, desertif icaltion Process is developing. From the viewpoint of ecological management and protection of the environment and resources it is appropriable to establish the physical reserve in lower reaches of the Keriya River, bring the maintenance and regeneration of natural vegetation into overall management of the water resource ecosystem of the whole river valley.