Abstract: Thirty typical plant communities were selected in 5 parks around the West Lake in Hangzhou, Zhejiang province. The annual carbon sequestration and carbon emissions of these communities were estimated by i-Tree software and life cycle assessment method. The effects of tending and management, and plant community structure on carbon budget were analyzed, and the relationship among canopy density, plantation density, and ratio of tree and shrub with the carbon budget of plant communities were explored. The result demonstrated that the average carbon budget of sampled communities was 3 209.40 kgC·a-1/ha, with an average carbon sequestration of 11 209.87 kgC·a-1/ha and average carbon emission of 8 000.47 kgC·a-1/ha. It showed that the carbon budget of the plant community could top the largest with the canopy density of 0.50-0.75, plantation density of 355-750 tree/ha, and the ratio of tree and shrub of 0.25-0.50. It concluded that the carbon budget of plant communities showed a trend of increasing first and then decreasing with the increase of canopy density, plantation density, and ratio of tree and shrub.