Abstract: The variation characteristics of soil organic carbon ( SOC) in different develop ing stages of Chinese firp lantations were studied in Dagang mountain of J iangxi Province. Correlation analysis and stepwise regressionanalysiswere used to investigate the influence of soil factors on SOC content. Results showed that SOC contentdecreased with increasing soil dep th. Significant variation characteristics of SOC contentwere found in different soillayers, with coefficient variation in the order of 40 - 60 cm > 20 - 40 cm > 0 - 20 cm, especially in the mediumforest soil. With the growth and development of Chinese fir p lantations, SOC content decreased from juvenile tomedium, and then increased from medium to over-mature. The SOC content had close correlations with totalnitrogen content and alkali-hydrolyzable nitrogen content. The SOC regression equations in different develop ingstages of Chinese fir p lantationswere established with high regression estimation p recision. Compared Beta suggestedthat soil nitrogen was the leading factor of SOC content variation.