Abstract: Tarim River is the longest interior river in China, its mainstream is 1, 224 km long fromAral to Taitema Lake. Tarim River watershed has abundant solar resources and relatively suffi-cient water resources which can staisfy the water consumption of agriculture, forestry and ani-mal husbandry if it is utilized rationally. However, the streamflow at the lower reaches ofTarim River is being dereased continuously and it is almost cut out downstream from Daxihaizibecause of the irrational exploitation and utilization of water resources at the upper and middlereaches. Thus the ecological environment is deteriorated and the stream water is seriously pol-luted in the watershed, which have resulted in great impact to agricultural irrigation and dailylife of local people. Therefore, the stream water pollution must be paid a big attention to in therealignment of Tarin River watershed. In this paper, the stream water quality was monitoredat Xidaqiao Hydrologic Station of Aksu River, a source stream of Tarim River and at Aral Hy-drologic Station of the mainstream during the period from June, 1997 to May, 1998. The situ-ation and causes of the stream water pollution are analyzed. The results show that, currently, an annual salt quantity of 4.02 million tons is drained from farmland into Tarim River alongwith drained water, but the stream volume of the mainstream of Tarim River was decreasedfrim 5.62 billion m³ in the late 1950 s to 3.854 billion m³ in the mid 1990 s, thus the mineral-ization of stream water is raised. According to the present situation, some control ways forstream water pollution are put forward, which include to control drained water away fromTarim River, to implement well-draiming way for lowering groundwater level and improvingsoil, to divert the drained water, fresh water and floodwater separately, and to ensure the feedof the mainstream of Tarim River from the source streams. It is suggested to strengthen themanagement of drainage and water consumption for a sustainable development in the water-shed.

Key words: Tarin River, stream water pollution, control way