Abstract:The effects of green manuring rotations in summer fallow period on soil water and water use efficiency (WUE) in winter wheat were studied in extremely dry year during wheat growth period in different altitude-regions by large-scale field comparing method. The results showed that the soil water storage was higher at sowing date and mature date of wheat under different green manuring rotations at altitude of 998 m than that at 495 m,and the soil water storage difference in 0—100,100—200,and 200—300 cm was extremely significant between two altitudes,respectively. The soil water storage was decreased with green manuring date delay on same rotation in 0—100 cm and 100—200 cm at sowing date at all altitudes. The soil water storage difference in 0—100,100—200,and 200—300 cm was extremely significant,significant,and not significant between sowing date and mature date,respectively. The soil water storage proportion of mature date to sowing date was increased with soil layer increasing in 0—100,100—200,and 200—300 cm at altitude of 998 m,while the proportion was higher in 100—200 cm than that in 200—300 cm at altitude of 459 m. During wheat whole growth period in same green manuring stubble between high altitude and low altitude,soil water consumption showed extremely significant difference in 100—200 and 0—200 cm,significant difference 0—100 cm and 0—300,and no difference in 200—300 cm. The soil water consumption of different layer was correlative with the soil water storage in wheat sowing stage of same green manuring stubble at two altitudes. The wheat yield and water use efficiency at 998 m altitude were higher than those at 495 m in same green manuring stubble. The yield difference was extremely significant,while the water use efficiency showed no difference. The early corn green manuring stubble and deep tillage stubble had higher water use efficiency at 998 m and 495 m. The study provided theoretical foundation and technical support for improving farmland quality and soil water bearing capacity by green manuring in different regions.