Forest biomass is the basic information for studying energy flow and material cycle in forest ecosystem.Forest carbon sink analysis is of significance to achieve carbon neutrality before 2060.Based on the data of four continuous forest inventories in Sichuan Province,this paper systematically compared the differences in biomass and carbon storage estimation between the single-tree model summation method and the expansion factor method,established the carbon sequestration rate models of 19 major arboreal stands,and analyzed its carbon sequestration potential and distribution of carbon storage density.The results showed that there was no statistical difference in biomass and carbon storage estimation between the single-tree model summation method and the expansion factor method.The differences in biomass and carbon storage density of forest vegetation mainly came from the estimation differences of arbor stands.The fitting determination coefficients of carbon sequestration rate models of major arbor stands were all greater than 0.7.The carbon sequestration potential of poplar stand,birch stand,broad-leaved mixed stand,softwood broad-leaved stand,and hardwood broad-leaved stand increased rapidly during young age.The carbon sequestration potential of the coniferous and broad-leaved mixed stand,fir stand,Chinese pine stand,cypress stand,coniferous mixed stand,and spruce stand was greater during mature age.The forest vegetation biomass and carbon storage density increased gradually in Sichuan from 2002 to 2017,showing a trend of transfer from low density to high density.