As one of the important ecological ecotones in alpine regions, the treeline ecotone is a sensitive area in response to climate change. Soil carbon stock is abundant within the treeline ecotone and its carbon turnover plays an important role in the global carbon cycle. Exploring soil organic carbon mineralization and its temperature sensitivity in the treeline ecotone is important for predicting soil carbon cycling processes in alpine regions under the background of climate change. In this study, we performed an incubation experiment at different temperatures (15℃ and 20℃) for 90 days based on soils from the treeline ecotone (forest, treeline, shrub) in the Gongga Mountain on southeastern Qinghai-Tibet Plateau. Soil organic carbon mineralization rates were measured, cumulative mineralization per unit of soil organic carbon and temperature sensitivity were calculated. At the same time, we analyzed the relevant factors affecting them. The results showed that the soil organic carbon mineralization rates were significantly influenced by temperature and vegetation types. Warming significantly increased soil organic carbon mineralization rates, while the mineralization rates also had significant differences among vegetation types, the values showed that forest > treeline > shrub. We used the cumulative mineralization per unit of soil organic carbon to characterize the soil organic carbon stability. After 90 days of incubation, the cumulative mineralization per unit of soil organic carbon from forest, treeline to shrub was 12.33 mg/g, 12.99 mg/g, and 10.53 mg/g at 15℃, while 19.16 mg/g, 21.14 mg/g, and 16.14 mg/g at 20℃, respectively. The values for shrub soils were significantly lower than forest and treeline soils, indicating that shrub soils had higher stability. The cumulative mineralization per unit of soil organic carbon was significantly positively correlated with the percentage of particulate organic carbon and negatively correlated with the percentage of mineral-bound organic carbon, but had no significant correlation with acid hydrolysable carbon fractions, indicating that the chemical protection formed by the combination of soil organic carbon and minerals significantly affected the stability of soil organic carbon in the treeline ecotone in the Gongga Mountain. The temperature sensitivity coefficient Q₁₀ of soil organic carbon mineralization in the treeline ecotone was 2.45±0.25, showing a high temperature sensitivity. The results of correlation analysis indicated that soil pH and C:N were the main factors to influence temperature sensitivity, while similar soil pH and C:N within the treeline ecotone might be an important reason for the lack of significant differences in Q₁₀ values between different vegetation types.