It was researched that the numbers and biomass of soil microorganisms in different development stage of Chinese fir plantation in Shanxia farm of Sub-tropical Forestry Center, CAF in Fenyi country, Jiangxi Province. The trend of the numbers and biomass of soil microorganism, the numbers of bacteria and the content of available N, P was decreased from juvenile to medium plantation, and increased from medium to mature plantation. But it was not found the trend from the numbers of fungi and actinomycetes, the content of available K,total N, P, K, in different development stage of Chinese fir plantation. Key words: Chinese fir plantation, soil nutrient contention, soil microbial numbers, soil microbial biomass