Abstract: From the aspects of actual weather conditions and circulation characteristics, a precipitation process in Tongliao City,Inner Mongolia was analyzed according to various numerical forecasts. The results show that the precipitation in Tongliao City was mainly caused by the situation ＂high in the east and low in the west＂ at the low layer that was conducive to the northward transportation of warm and wet flow, the southward movement of upper cold air over Lake Baikal, and the intersection of cold and warm air over the city.