Abstract: Based on the forest lightning fire data from 1980 to 2018 in the Greater Khingan Mountains, Inner Mongolia, this study uses quantile regression, Mann-Kendall trend test, and sliding t-test to analyze the frequency and spatial changes of lightning fires at 2 scales: temporal (year, fire prevention period, and season) and spatial (administrative division and altitude). The results showed that the number of lightning fires in Greater Khingan Mountains, Inner Mongolia, was less from 1980 to 1999, and showed an upward trend from 2000 to 2010. The fire rose sharply from 2000, and showed a downward trend from 2011 to 2018; spring and summer are the main seasons for forest lightning fires, and the number of lightning fires in winter is less, and the fire in the fire danger period shifts and extends to summer. The spatial distribution is characterized by a decreasing trend from the northeast to the southwest. Lightning fires occur frequently in Oroqen Autonomous Banner, Arong Banner, Erguna city and Molidawa Daur Autonomous Banner. Greater Khingan Mountains in Inner Mongolia is rich in forest resources. We should strengthen the fire prevention monitoring and prevention measures of forest lightning fire in spring and summer, and adjust the fire prevention resources appropriately, so as to further reduce the number of fires in Greater Khingan Mountains.