AS a key component of ecosystem carbon budgets, soil carbon is the largest carbon pool of forest ecosystem. Soil microbial biomass carbon is an important component of carbon cycle of the terrestrial ecosystem. In order to explore the effects of different forest types on soil active carbon pool, we chosed Alpine Shrub AS,Rhododendron Forest RF,Abies georgei var. smithii forest AGSF and Picea likiangensis var. linzhiensis forest PLLF as experimental sites in the Sygera Mountainous southeast Tibet. Soil organic carbon SOC, total nitrogen TN and soil microbial biomass were studied at different soil horizon. There is higher LOC(labile organic carbon)at higher-elevation vegetation types in comparison with lower-elevation ones. At 0-10cm soil layer, SOC among the AS, RF, AGST and PLLF were significantly different P＜0.05. However, no trend was found for SOC at 10-20cm and 20-40cm. At the AS site, TN were significantly different at 0-10cm soil layer P＜0.05. There were no significant difference for the AS, RF, AGST and PLLF sites P＜0.05. At 10-20cm soil layer, there were significant difference for them(P＜0.05). However, no regularity was found for SOC at 20-40cm. At different depths, the soil microbial biomass was significantly correlated to soil organic carbon. The SMBC and SMBN was positively correlated with SOC, and the SMBN or its ratio was also positively correlated with the SMBC content and its ratio. The SMBC and SMBN increase with increasing elevationt in the Sygera Mountains. As shown, the total SOC, readily oxidizable carbon and particulate organic carbon decreased with increasing soil horizons. The rations of particulate organic carbon to total SOC content and the readily oxidizable carbon to total SOC content were different in their range. Moreover, their ratios decreased with increasing soil horizons. The active SOC was significantly related to total SOC. In addition, the relationship between readily oxidizable carbon and particulate organic carbon was also significant P＜0.05.