Abstract: In this paper,taking the soil layer of zero to 4 cm thickness of 3 different forest types(pure fir forest,pure birch forest and mixed forest of birch and fir,in Liangtaigou of Lixian County of Sichuan as the research object,researches were conducted on the change rule of soil physical and chemical properties of the different forest types in order to provide theoretical basis for the sustainable development of artificial forests. The results of the study showed that (1) their soil water content decreased with the increase of the soil depth:mixed forest > pure birch forest > pure fir forest (2) changes of particle content in soil mechanical composition of different forest types were as follows:sand > silt > clay,and the sand content in the soil:pure fir forest > pure birch forest > mixed forest of birch and fir,and yet coarse silt,fine silt and clay displayed an opposite trend (3) The soil pH value was between 5.3~5.8,pH value of 3 forest types increased with the increasing of soil depth,but there was no significant difference in the pH value. Among them,the pH value of fir forest was the lowest and the pH value of mixed forest was the highest; (4) 3 kinds of soil organic matter,total N,available P and available K all decreased with the increase of the soil depth,showing obvious "accumulation" phenomenon. Their contents were as follows:pure birch forest > mixed forest of birch and fir > pure fir forest.