Abstract: This paper was deal with the study of the optimal sowing date,yield and economic benefit of winter rapeseed in cold dry region of Inner Mongolia. The result suggested that the suitable sowing date was 15 to 20d in august. Yield of Winter rapeseed No.6 and Winter rapeseed No.7 was about 200kg/667m2,the economic benefit was 800RMB per 667m2. Rotation of Wheat-Winter rapeseed-Sunflower was adopted. It was important for the cultivation of winter rapeseed,sustainable growth of argriculture and ecological system maintaining in dry cold regions of Inner Mongolia.