Abstract: Mann−Kendall trend test and sliding t−test were used to analyze the trend and abrupt change of Xilingol grassland fire data from 1981 to 2018, and the quantile regression was used to study the altitude factor affecting the grassland fire area and finally obtained the change trend of Xilingol grassland fire in space. The results indicate that the number of grassland fires in Xilingol generally shows a "stepwise" decreasing trend, mainly occurring in spring and autumn, accounting for more than 90% of the total number of fires throughout the year. The abrupt change year in the entire year, fire prevention period and the spring grassland fires are from 1994 to 1995, the abrupt change in autumn occurred in 1990 and there were no abrupt change years in summer. Compared with the statutory fire prevention period, the fire risk period of Xilingol grassland shifted toward summer, and has a tendency to shorten. Xilingol grassland fires occur more frequently in East Uzhumqin Banner and West Uzhumqin Banner, with an overall increasing trend from southwest to northeast, and the burned area has a decreasing trend with the increase of altitude. The study suggests that fire prevention publicity in the Xilingol grasslands should be strengthened before spring and autumn each year, and attention should be paid to summer fires. Focus on the prevention and monitoring of grassland fires in the low elevation areas of East Uzhumqin Banner, West Uzhumqin Banner and Xilinhot City, and reasonably allocate fire prevention resources.