The features of the large scale circulation which creates East Asia low-level jet in winter and the relationships of the low-level jet and heavy snow or snowstorms in Inner Mongolia are analyzed.The results show that when there is westerly upper jet in middle latitudes and if the cold low pressure trough in central Asia moves eastward and split in two ones,the East Asia low-level jet which causes heavy snow or snowstorms in Inner Mongolia will be created easily.It is pointed out that the process of adjustment of the westerly belt-large scale circulation could be a sign of the middle range prediction of heavy snow or snow storms in Inner Mongolia.