Abstract: The characteristics of environmental factors causing summer forest fire were studied through collection and analysis of the relative forest fire data and materials during the period of 2000–2004 in Daxing'an Mountains of Heilongjiang Province. Based on the average daily indicators of surface meteorological data of Daxing'an Mountains in the summer fire season (from June 16 to September 14) during the period of 1966–2015, the mutual response mechanism between climate change and forest fire was studied. The results show that Daxing'an Mountains are mainly affected by surface fire and ground fire in summer, and in which, the ground fire broke out the most in the fuel type of Larix gmelinii−Pinus pumila with a proportion of 70%, while it has a high percent in the sunny slope than in the shady slope. The crown fire mainly break out in the fuel type of P. pumila elfin wood, and the frequency of the crown fire increases with the slop increasing. In the south slope, the grown fire is more prone to break out than in the north. The climate of Daxing'an Mountains during the period of 1966–2015, nearly 50 years, tends to be warm and dry, so the fire risk is increasing in summer. These changes in climate will lead to a high temperature and dry environment within the forest, devastating fire will pose a threat to the main tree species of L. gmelinii in Daxing'an Mountains. The summer forest fires in Daxing'an Mountains are mainly caused by lightning. The data and theory of correlation analysis on environmental factors and forest fire can provide decision-making reference for forest fire prevention institutions.