An erosive action resulting from the frequent melting and freezing of snowfields in ice-margined climates. Snow erosion occurs in the polar and sub-polar regions where there is no ice cover, and in the alpine zone below the snow line and above the tree line. The average annual temperature there is about 0°C, and it is a permafrost zone. The alternating freezing and thawing at the edge of the snowfield, on the one hand, breaks up the surface material through ice cleavage; on the other hand, the snowmelt water takes away the crushed fine-grained material, so the snow erosion action includes two kinds of action: stripping and carrying. With the deepening of the bottom of the snow field, the periphery expanded, the hillside gradually formed around the slope of the wide shallow basin-like depression, that is, the snow melt depression. Its morphology, genesis and spatial distribution are different from the ice bucket, but the two are related. When the climate further cold, snow line decline, snow erosion depression can develop into ice bucket; Conversely, the climate warming, glacier retreat, ice bucket can be degraded to snow melt depression. The mode and rate of snow erosion vary under different physical and geographic conditions. In the lower latitude, precipitation, annual freezing and thawing of the number of days, the rate of snow erosion faster, snow erosion depression deep, large area. For example, in the Xiaoxinganling area of northeast China, snow-eroded depressions are very common. On the contrary, in the high latitude, low precipitation, low summer temperature place, snow erosion effect is weak. The effect of the ground slope is: slope steep > 40 °, the snow field is not easy to exist; snow erosion on the flat land is extremely slow; 30 ° or so on the slopes, snow erosion is the most active.