In the Chifeng Saihanwula Integrated Shelter Forest Demonstration Base established by Inner Mongolia Agricultural University and Inner Mongolia Hesheng Ecological Science and Technology Researcher Co.,Ltd.,the Larch plantations with different stand densities (1 407,1 675,2 680 plants/hm²) were taken as the research object.Three standard plots each were set up the soil stratified,and the physical and chemical properties of the soil measured indoors.The results showed that the soil physical and chemical properties of Larix principis-rupprechtii plantations with different afforestation densities were significantly different.When the stand density was 1 407 plants/hm²,the soil bulk density was the smallest (0.97),the total porosity (62.6%) and the water content (14.75%) were the largest.The accumulation process of organic matter was slow and there was no significant change,However,the contents of total N (110.06g/kg),effective P(0.57g/kg) and effective K(29.11g/kg) in the topsoil were highest at the stand density of 1 407 plants/hm ².