Abstract: Effects of plant-cultivated pattern,tillage and nutritional level on water use efficiency in black soil region of Northeastern China are researched.The results show that water use efficiency of optimized patterns on wheat-corn-soybean ecosystem is highest,that of zonal tillage is 1.42kg/hm²·mm, under natural precipitation,water use efficiency of high fertilizer region is highest under the suitable moisture,water use efficiency of high or middle fertilizer and organic manure region is approximate,and water use efficiency of middle fertilizer region is highest under sufficient water.