Abstract: The Boreal forest has been disturbed by forest fire in different degrees for a long time, which plays a key role in nutrient cycling in forest soil. In order to explore the soil nutrient characteristics after forest fire under different site conditions, the soil of burned area in Huzhong forestry bureau of Greater Khingan Mountains was selected as the research object, soil samples were collected from four plots with similar forest age, slope location and different site conditions. Main chemical properties of soil pH, soil total carbon（TC）, soil total nitrogen（TN）, soil total phosphorus（TP）, soil organic carbon（SOC） as well as two soil enzyme activities（cellulase（CBH） and β-glucosidase（βG）） in different areas（interior area, edge area, and unburned area） were measured and analyzed. The result showed that the Larix gmelinii-Betula platyphylla mixed forest had the most abundant soil nutrient conditions, and the soil nutrient content after a fire was still better than the other three sample sites. Compared to the unburned area, TC and SOC in the edge area of each forest type decreased significantly, the activity of soil enzyme CBH and βG showed a significant upward trend（P＜0.05）. Compared with the edge area, TC, TN and SOC were significantly decreased（P＜0.05） in the interior area of Larix gmelinii-Pinus pumila forest mixed forest dominated by Larix gmelinii, while the contents of TC, TN and SOC were significantly increased（P＜0.05） in the Larix gmelinii-Betula platyphylla mixed forest, and the activities of CBH and βG in the interior area were significantly decreased compared with the edge area, while the enzyme activity in the interior area of the Larix gmelinii-Betula platyphylla mixed forest was significantly higher than that in the edge area（P＜0.05）. Fire disturbance had no significant effect on soil p H in these forest types（P＞0.05）. Fisher discriminant analysis showed that the overall differentiation of sample distribution was worse when the burned area was taken as the dependent variable than when Pinus pumila-Larix gmelinii forest mixed forest dominated by pinus,Pinus pumila-Larix g melinii forest mixed forest dominated by larch,Carex-Larix gmelinii forest,Larix gmelinii-Betula platyphylla mixed forest was taken as the dependent variable. In conclusion, forest fire significantly changed the soil nutrient contents and soil enzyme activities in four forest types, but it had less effect on p H. The difference in soil nutrients between forest types was greater than that in different burned areas. At the initial stage after fires, the authorities should take different plans for these forests to promote restoration. This study can provide theoretical support for evaluating the effect of fire disturbance on soil nutrient change in the cold temperate zone Larix Xingan forest, and provide reference for the formulation of forest restoration plan after fire in the northern coniferous forest.