Abstract: The geographic distribution data of the three precious hardwood broad-leaved tree species, Fraxinus mandshurica, Juglans mandshurica and Phellodendron amurense in the Maoershan area were collected through investigation and consulting data. And the suitability distribution of three precious hardwood broad-leaved tree species in Maoershan area was studied by using GIS technology and random forest model, combined with the topographic and soil data of the target tree species subcompartment. Results showed that, the accuracy rates of the random forest models in the ten datasets were all above 70%. When Ntree（number of trees grown）=500, the average accuracy of the random forest model was 75.2%; when Ntree=1 000, the average accuracy of the random forest model was 75.4%, and the AUC of the group datasets were all above 0.7, and the average AUC was 0.746. In the ten datasets, mean decrease accuracy and mean decrease Gini of altitude were the largest, mean decrease accuracy of slope position was the smallest, and mean decrease Gini of landform was the smallest. The target tree species had the highest growth suitability within the altitude range of 200-300 m. As the altitude increased above 300 m, the growth suitability of the target tree species was lower as the altitude increased. When the slope was 0°-10° and 30°-35°, the growth suitability was the highest in the range. As the slope position changed from top to bottom, the growth suitability of the target tree species was getting higher and higher. The growth suitability in the three directions of southwest, south and north was the highest. The growth suitability was highest in plain areas. When A layer（eluvial horizon） thickness was greater than 15 cm, the growth suitability of the target tree species became higher and higher. When AB layer（eluvial horizon and deposition layer）thickness was in the range of 10-25 cm, the growth of the target tree species was the most suitable. The order of affecting environmental factors importance sorting of the suitability distribution of the three precious hardwood broad-leaved tree species in the Maoershan area was altitude, AB layer thickness, slope, slope aspect, A layer thickness, landform and slope position in descending order. They were mainly suitable for distribution in the southern and northwestern areas of Maoer Mountain, with an altitude of 200-300 m, a gentle slope, a soil layer thickness of 15-25 cm, a north-south aspect, a plain landform, and a downhill position.