The distribution of snow cover over the Northern Hemisphere, the facts of anomalous snow cover influencing the climate in China and the influence mechanism are systematically reviewed and summarized.The Tibetan Plateau, the Mongolian Plateau, the European Alps and the mid-west of North America are the key areas of snow cover over the Northern Hemisphere, and the Tibetan Plateau is the most sensitive region of snow cover anomaly.Snow cover is widely distributed in China with three high value regions over Xinjiang, Northeast China and the Tibetan Plateau.Conclusively, there is a decreasing tendency for snow cover in the Northern Hemisphere, but a weak increasing trend in China.There are opposite effects of winter-spring snow cover in Eurasia and the Tibetan Plateau on summer precipitation in China.The mechanism of snow cover influencing climate in China is explained as:The snow cover albedo effect plays a major role in winter and the snow cover hydrological effect in spring-summer.Snow cover is a very important physical factor in short-term climate prediction of China.It has great significance to strengthen research in this area for improving the accuracy of short-term climate forecasting in China.