Mountain soil has strong heterogeneity and high carbon density. Studying the storage,spatial distribution patterns and influencing factors of soil organic carbon in mountainous area is of great significance for understanding the soil carbon-atmosphere feedback under the future climate change scenarios. Mountainous areas in the Hexi Region are characterized by complex topography,large gradients of water and heat,thus an ideal area to study the pattern of soil organic carbon and its influencing factors. In this study,126 soil profiles were used to investigate the storage and spatial distribution of 0-100 cm soil organic carbon and its relationship with environmental factors in mountainous areas in the Hexi Region in Gansu. The results showed that the average soil organic carbon density of 0-100 cm in mountainous areas in the Hexi Region was 15.047.24 kg·m~(-2) and the area of soil organic carbon storage was 1.370.66 Pg,of which 50% was stored in alpine meadow and sub-alpine shrub meadow zone. Specifically,the soil organic carbon density in different vegetation types decreased as the following order: sub-alpine shrub meadow ( 41.1518.47 kg·m~(-2) ),mountain meadow steppe ( 40.269.59 kg·m~(-2) ),mountain forest ( 34.57 14.52 kg·m~(-2) ),alpine meadow ( 29.19 14.58 kg·m~(-2) ),mountain steppe ( 19.28 11.33 kg·m~(-2) ),desert steppe ( 9.834.14 kg·m~(-2) ),alpine steppe ( 8.592.47 kg·m~(-2) ),alpine desert ( 5.89 3.18 kg·m~(-2) ),steppe desert ( 5.163.06 kg·m~(-2) ),temperate desert ( 5.003.35 kg·m~(-2) ). In addition, the spatial distribution of soil organic carbon was significantly correlated with topography and climatic factors. Soil organic carbon tended to increase at first and then decrease with the elevation. The organic carbon density on the shady slopes was significantly higher than that on the sunny and semishady slopes. Soil organic carbon density increased with the annual mean precipitation. The relationships between soil organic carbon and mean annual temperature were characterized by an increasing trend at first,then an decreasing trend.