[Objective] To assess the land use change and carbon storage change in the future under different scenarios in the Xiaoxing'an Mountains region of Heilongjiang Province, in order to optimize ecosystem services and provide scientific reference for the construction of the northern ecological security barrier.[Method] Based on land use data from 2000, 2010, and 2020, simulate the land use changes in the Xiaoxing'an Mountains region for the year 2030, and assess the carbon storage under three different scenarios: natural development, ecological protection, and urban development.[Result]① Between 2000 and 2020, the land use pattern in the Xiaoxing'an Mountains region of Heilongjiang Province underwent significant changes, with forests and grasslands continuously shrinking, especially forests, which mainly transitioned into cultivated land. ② The carbon storage in the Xiaoxing'an Mountains region of Heilongjiang Province in 2000, 2010, and 2020 was 220415.25×10?t, 220200.94×10?t, and 219139.71×10?t, respectively, showing a trend of annual decline. ③ From the perspective of carbon sequestration, by 2030, the ecological protection scenario is significantly advantageous compared to the natural development scenario, with an increase of 1932.98×10?t, effectively alleviating the downward trend of carbon storage, providing a strong basis and guidance for subsequent policy-making.[Conclusion] The future should continue with scientific ecological policies to maintain the ecological security of the Xiaoxing'an Mountains region in Heilongjiang Province, enhance carbon sink capacity, and help build a northern ecological security barrier.