Abstract: In order to evaluate the status and role of fire in Mongolian Scotch pine(Pinus sylvestris var.mongolica) forest of Daxinganling mountain,studies were conducted in 3 sampling plots in the Mordaoga Forestry Region.We defined the years and heights(h) of fires which happened in sampling plots by a method of fire scar analysis.Fire intensity(I) is calculated by an experiential formula,and the diameter at the breast height (DBH) after each fire concludes from the materials of DBH measured in the field.Results showed that 10 fires happened in 3 sampling plots from 1887 to 1976,h ranging from 0.45～3.32?m and I range from 48～3?690?kW/m and mean fire interval(t_(MFI)) is about 19.8 years.Limited data on fire history and stand DBHs distributions after fires showed:high intensity fire disturbed the stand development and compelled stand to restart the regeneration and succession;medium and low intensity forest fires as a natural selection force,suppressing other trees,shrubs and weeds with low resistance against fires and accelerating soil nutrient cycling,those are in favor of survival for Mongolian Scotch pines;t_(MFI) and I generally have an inverse relationship.Therefore,it will raise the risk of high-intensity fire occurrence to prevent fire from forest in a long term.