Abstract: By taking the plantations of 12 common afforestation species in the subtropical zone as the research object, the differences of the properties of leaf litters, and the characteristics of soil physicochemistry and microbiology of different tree species were analyzed, in order to explore the relationship between the calcium content of leaf litters and the indexes of soil acidification and microbiology. The results showed that the calcium content of leaf litters among different tree species ranging from 1.1 to 9.8 g·kg^-1, among which the calcium content of leaf litters in Phoebe bournei plantation was the highest, and the calcium content of leaf litters in Pinus elliottii plantation was the lowest. The comparison of soil chemical and biological characteristics between the different tree species showed that the soil pH value of Phoebe bournei plantation was the highest, while that of Pinus elliottii plantation was the lowest. Moreover, the available phosphorus content in the soil of Phoebe bournei plantation was second only to that of Phyllostachys pubescens forest, but the composition of soil microbial community of Phoebe bournei plantation was significantly different from that of other tree species, which was mainly manifested as that the abundance of soil bacterial community was significantly lower than that of other tree species. Through the correlation analysis, it was found that the calcium content of leaf litters of different tree species was positively correlated with the soil pH and available phosphorus content, while negatively correlated with the abundance of soil bacterial community. The results showed that the calcium content of leaf litters had a significant effect on the acidity index of the undergrowth soil, as well as the nutrient cycling and microbial process in the soil.