Abstract: Due to climate change, overgrazing and overcultivation, grassland degradation and other ecological problems in Xinjiang have attracted increasing attention. In this study, MODIS NDVI remote sensing data products are used to monitor and analyze the grassland status in Xinjiang from 2001 to 2020. The pixel binary model, grassland degradation index based on coverage change, cold/hot spot analysis and other methods are used to obtain the temporal and spatial characteristics of grassland degradation in Xinjiang according to the national standard of grassland degradation grade classification, and then the influencing factors are analyzed. The results show that:①the coverage of grassland in Xinjiang is increasing with a main variation degree of stability (55.4%), and the distribution shows a gradually decreasing trend from north to south.②In the past 20 years, the degradation level of grassland coverage in Xinjiang was in a state of moderate to mild degradation, with the north mainly in an undegraded or mildly degraded state, while the east and south were mainly in a state of mild to moderate degradation, and the grassland was in a recovering trend during different study periods.③The grassland degradation index in Xinjiang shows an overall downward trend, increasing first and then decreasing in northern Xinjiang, decreasing continuously in eastern Xinjiang, and slightly increasing in southern Xinjiang. The cold/hot pattern shows that the cold spot increases and the hot spot decreases. It means, grassland degradation has weakened and is gradually recovering.④The grassland type caused by human activities is mainly transformed into bare land and farmland, and the grassland area decreases by 1.676 million hm². The temperature shows a mean temperature inhibition, a high-temperature promotion, and a low-temperature inhibition effect on the grass coverage.Precipitation has a promoting effect on grassland coverage.The results of this study can provide targeted guidance for the degradation of grassland in Xinjiang at the regional scale and provide a decision-making basis for the protection and restoration of the ecological environment.

Key words: grassland, vegetation coverage, grass degradation index, cold/hot spot analysis, influencing factors