Abstract: The Loess of middle Kunlun Mountain is mainly dispersed over the mountain area with elevation of 3000－4000 meters. It is tendencily decreasing with the rising of the elcvation. the components of heavy minerals in loess have little bearing with the depth of sampling and the elevation. According to analysis and determination to the components and characteristics of minerals in the loess with polarizing microscope and size analysis and microstructure characteristic of the loess. we get the following initial result；The mineral in the loess in northside of middle Kunlun Mountain mainly stem from the south duncs of Tarim Basin. The forming environment is arid. the forming time is the later period of the later-Pleistocene, and wind power is played a decisive role on forming of loess.