Abstract:Under the background of global warming, soil organic carbon (SOC) has become one of the most important issues in study of global carbon cycle and global change ecology, especially in the alpine timberline ecotone with sensitivity of climate change. Therefore, both of SOC contents and density (SOCD) were studied under subalpine meadow (CD), Larix principis-rupprechtii forest (HL) and Picea meyeri×Larix principis-rupprechtii mixed forest (YH) near the alpine timberline in Wutai Mountain. The results showed that SOC contents of all three vegetations were decreased with soil depth. SOCD values of studied soils were increased with soil depth. SOC and SOCD were mainly concentrated in surface soil, showed surface assembly effect. As the same as the subalpine soils in China, in our study region, total SOC contents and SOCD of subalpine forest (HL, YH) soils were both larger than those of subalpine meadow soils (CD). But it was different from subalpine soils in other continentals except Asia. Total SOC contents and SOCD in subalpine soils of Wutai Mountain were approximately equal to the mean total SOC and SOCD of subalpine soils in China, and they were larger than those of other continentals except Asia. The differences of significant impact factors (P<0.05) on subalpine SOC were observed between Wutai Mountain and global scale. On the global scale, soil depth and climate factors (P<0.05) in subalpine forests had more significant effects on SOC than subalpine meadow/grassland (P>0.05). Thus, in Wutai Mountain, subalpine forest soils have more capability of carbon sequestration than subalpine meadow soils. Their total SOC contents and SOCD are both approximately equal to the mean values of Chinese national scale. Carbon pool of subalpine soils in China takes a leading position from a global view. However, more researches are desired in order to reduce the uncertainties in multi-scale studies.