To monitor scientifically the snow cover and its change characteristics in the Qilian Mountains if of important significance for the regional climate research, the development and utilization of snow meltwater, the forecast of natural disasters and ecological environmental protection. Based on the MOD10A2 snow products and meteorological data from 2001 to 2017, the dynamic changes of snow cover in the Qilian Mountains and its relationship with temperature and precipitation were analyzed. The results show as follows: (1) The average snow cover area in the Qilian Mountains was about 5 * 10~4 km~2 which accounted for 25. 9% of its total area. The snow cover between 2001 and 2017 has a large inter-annual fluctuation trend showing a pattern of letter Mwhich meant the Qilian Mountains has two peaks and one trough in terms of the snow cover in a year. The peak positions appeared in November and January,and the trough appeared in July. The snow cover had a relatively large seasonal variation trend which had a bigger decreasing tendency in summer and winter than that in spring and a slight increase trend in autumn. (2) The snow cover area in Qilian Mountains was mainly located in the places of an altitude in the range between 3 000 m and 5 000 m,and the snow cover tended to increase with the elevation. There was a big difference in snow cover area in different aspects in Qilian Mountains yet with a small snow coverage rate. The high-snow frequency zones showed a typical banded distribution which is basically consistent with the distribution of the Qilian Mountains,and the areas with high value of snow accumulation were much more in the west than those in the east. (3) The preliminary analysis showed that the change of snow area in Qilian Mountains was more sensitive to the temperature.