The Tibetan Plateau （TP） is sensitive to climate change， where snow plays a vital role in the regional hydrological cycle and climate system. This paper uses the daily cloud-free snow cover remote sensing data from 1980 to 2020 to analyze the distribution characteristics and variation trends of the snow cover area （SCA） and snow cover days （SCD） for a hydrological year from August 1 to July 31 in the next year over the TP. The results show that： （1） The snow in the TP shows an apparent spatial differentiation and a vertical zonal distribution characteristic. It is widely distributed in the high-altitude mountainous areas in the Amu Darya， the Indus， the Tarim， the Ganges， the Salween， and the Brahmaputra basins. （2） During the hydrological year， the snow cover extent shows a unimodal variation in the plateau with the minimum in early August and the maximum in mid-late January， accounting for 5.2% and 38.6%， respectively. （3） In the past 40 years， the average SCA shows a significantly decreased trend with 3.9×10⁴ km²·（10a）^-1 （P<0.05）. （4） The SCD in the study area mainly shows a significant decrease with 0.47 d·a^-1. Up to 71.4% of the plateau shows a decreasing trend， and 55.3% of the area is significantly decreased （P<0.05）. And in 17.1% of the region， the SCD shows a significant increasing trend， and it is mainly distributed in the high-altitude mountainous areas above 5 200 m. Moreover， in the areas from 5 200 m to 5 900 m， the increase in SCD increased with altitude.