Snow cover is an important component of the cryosphere,which has an insulating effect on the ground. When snow melts,heat absorbing would reduce land surface temperature. Therefore,snow affects the growth of frozen ground,and is sensitive to climate change. Spatial and temporal variations of snow depth in frozen ground regions of Northeast China were analyzed by using spatial and statistics analysis function of GIS, based on the daily dataset of snow depth from 1979 to 2014. The results showed that the annual snow depth was 2.92 cm averaged from 1979 to 2014,with the maximum annual mean snow depth in the patchy permafrost regions and the minimum one in the seasonally frozen ground regions. Snow depth had decreased with the rate of 0.07 cm·( 10a)~(- 1),and the decreased area accounting for 39.77% of the total. The annual mean snow depth mutated in 1986 and then followed a decreasing,which was in accordance with the air temperature mutation. Affected by the terrain and the air temperature changing,the reduction of annual mean snow depth and the sensitive range mainly appeared in the patchy permafrost regions. Air temperature is main controlling factor to the annual mean snow depth in Northeast China. Precipitation,wind speed,humidity and sunshine duration can also influence the depth of snow cover. The snow depth in seasonally frozen ground regions is more sensitive than that in permafrost regions.