Abstract: This study is based on the tree small class data of Ning’er county’s 2020 forest resources map, and uses the biomass expansion factor method to estimate the carbon storage and carbon density of Ning’er county’s arbor forests by dividing the dominant tree species (groups), forest categories, origins, age groups, altitude ranges, and township administrative district systems. The results show that: in terms of spatial distribution, carbon storage is unevenly distributed in various administrative regions. The difference between the towns with the highest carbon storage and the lowest is more than 1 million tons. They are mainly distributed in areas with an altitude of 1000~2000 m, accounting for 91.12% of the total carbon storage of arbor forests. The carbon density will increase with the increase of altitude, with a maximum of 93.51t·hm^-2. In terms of tree species composition, oaks have the largest carbon storage of 5 595 344.00 t,and other hard broadleaf species have the highest carbon density of 66.21 t·hm^-2. The total carbon storage of Simao pine and oaks accounts for 82.9% of the county’s arbor forest carbon storage.Together they form the dominant tree species (group) in Ning’er county’s carbon storage, and the carbon density of broadleaf tree species is generally better than that of coniferous tree species.In terms of forest stand attributes, the carbon storage and average carbon density of natural arbor forests are higher than those of artificial arbor forests.The carbon storage of commercial forests (7 408 864.60 t) is greater than that of public welfare forests (3 985 692.50 t),but the carbon density of public welfare forests (51.65 t·hm^-2) is higher than that of commercial forests (38.77 t·hm^-2). Research shows that as the forest age increases, the carbon density of arbor forests will also increase. The area of medium-aged forests in Ning’er county accounts for 72.1%. It is expected that in the next few decades, carbon reserves will show a significant and sustained growth trend and reach a peak during the forest maturity period.It can be seen that carrying out forest carbon sequestration projects in Ning’er county has a good resource base and huge development potential.