［Objective］ The land use change and carbon storage change in the future under different scenarios in the Xiaoxing’an Mountains region of Heilongjiang Province were assessed， in order to optimize ecosystem services and provide scientific reference for the construction of the northern ecological security barrier. ［Methods］ Based on land use data from 2000， 2010， and 2020， land use changes in the Xiaoxing’an Mountains region in 2030 were simulated， and carbon storage under three scenarios（natural development， ecological protection， and urban development） was evaluated. ［Results］ ① From 2000 to 2020， significant changes occurred in land use patterns in the Xiaoxing’an Mountains region. The areas of forestland and grassland continuously declined， with forestland being particularly affected， primarily converted into cropland. ② Carbon storage in the region was 2.204×10⁹ t in 2000， 2.202×10⁹ t in 2010， and 2.191×10⁹ t in 2020， exhibiting a trend of annual decline. ③ In terms of carbon sequestration， by 2030， the ecological protection scenario offers significant advantages over the natural development scenario， with an estimated increase of 1.933×10⁷ t. This scenario effectively mitigates the decline in carbon storage and provides strong evidence for future policy formulation. ［Conclusion］ To maintain the ecological security of the Xiaoxing’an Mountains region， scientific ecological policies should be upheld to enhance carbon sequestration capacity and contribute to the development of a northern ecological security barrier.