There is a significant change of snow cover under global warming. More and more studies have focused on the variations in snow cover in the Third Pole (the Tibetan Plateau) and the Arctic because they are the typical distribution areas at high elevation (the Third Pole) and high latitude (the Arctic). Over the past 60 years, the trends of snow cover extent and duration have decreased significantly in the Third Pole and the Arctic, while there was a spatial inhomogeneity of change in snow depth. The change in snow cover is closely related to climatic conditions, atmospheric circulation, and the light-absorbing impurities. Snow cover also has an important feedback on climate, hydrological, ecological and human systems. The resolution of snow cover research would provide basic data and support for the regional economic and socially sustainable development.