Abstract: Soil carbon pools are important in terrestrial ecosystems because they regulate atmospheric CO₂ concentrations and maintain the global carbon balance. Soil organic carbon is the most important component of the soil carbon pool and an indicator of soil quality in ecosystems. This study considered the Manas River Basin on the northern slope of the Tianshan Mountains in Xinjiang as the research area to explore the spatial and vertical distribution characteristics of soil organic carbon in typical land-use types and the main influencing factors of spatial distribution. The results showed that the spatial distribution of soil organic carbon content showed a decreasing trend from south to north, manifesting as mountainous area (17.34 g∙kg⁻¹) > mountain front (11.57 g∙kg⁻¹) > plain oasis (10.22 g∙kg⁻¹) > desert (6.69 g∙kg⁻¹); the vertical distribution continued to decrease with the increase of soil depth, decreasing from 16.08 g∙kg⁻¹ (0−5 cm) to 7.91 g∙kg⁻¹ (40−60 cm). Pearson’s correlation analysis showed that soil organic carbon was significantly positively correlated (P<0.001) with elevation, total nitrogen, alkaline-hydrolyzed nitrogen, available phosphorus, and available potassium and significantly negatively correlated (P<0.001) with pH and bulk weight. Structural equation model path analysis showed that altitude, total nitrogen, alkaline-hydrolyzed nitrogen, available phosphorus, available potassium, pH, bulk density, and water content directly affected soil organic carbon content. Altitude, pH indirectly affected soil organic carbon content through affecting total nitrogen and alkaline nitrogen, while water content indirectly affected soil organic carbon content by affecting bulk density. The spatial distribution pattern of organic carbon in soil samples from the Manas River Basin was mainly influenced by environmental factors, such as temperature and precipitation. It showed the same spatial gradient changes with altitude. The fertile soil and cold and humid climate in mountainous areas are conducive to maintaining and increasing organic carbon content. Vegetation coverage in desert areas is low with insufficient litter and plant roots as sources of organic matter. However, human factors such as changes in land-use patterns, land management measures, and agricultural development in plain oasis areas have profoundly impacted the distribution of soil organic carbon. This study comprehensively analyzed the effects of different topographic climates, land-use types, and soil physicochemical properties on the distribution of organic carbon in the study area, providing an essential theoretical basis for ecological and environmental management related to carbon balance in arid and semi-arid regions.