Abstract: Using a quantitative statistical method, the carbon emissions from human respiration and fossil fuels and the carbon absorption by vegetation growth were compared among six districts (Furong, Tianxin, Yuelu, Kaifu, Yuhua and Wangcheng) in Changsha City. The results showed that the carbon emission from Yuhua District was the largest among the six districts, accounting for 24.82% of the total carbon emissions. But the carbon absorptions in Furong and Tianxin Districts were the lowest, only accounting for 1.87% and 12.08% of the total carbon absorptions, respectively. In general, the balance of carbon budget was better in Wangcheng and Yuelu than in other districts. In order to keep the balance of carbon budget in Changsha city, 84,297.32 hm2 of more woodland should be planned in the future to assimilate atmospheric CO₂. According to the economy development plan of Changsha city and in order to maintain the current carbon absorption rate of 48.15% until 2020, green areas need to be increased to a green coverage of 94.99% in keeping current spatial structure of green areas. Therefore, the vegetation structure needs to be optimized to reduce the energy consumption, to increase the green coverage to 60%, and to reserve 134,099.02 hm2 of woodland outside the city to assimilate more atmospheric CO₂.