Abstract: To know the changes of different developmental stages of plantation biomass and carbon storage of Toona sinensis in Sichuan Province,investigations were made on the biomass and carbon stock of artificial toona forest.The results showed that 3 years ~24 years old Chinese toona tree layer biomass variation range varied from 1.38 per hectare to 130.89 per hectare,the variation range of carbon storage was from 0.68 per hectare to 64.62 per hectare,the biological amount and carbon storage dynamics change fluctuations of 1 year ~20 years old toona trees were larger,20 years old toona trees had a trend of rapid growth,the biomass and carbon storage reached the maximum in the mature period of Toona sinensis;Simulation was done to build Chinese toona tree height,DBH and individual tree biomass model (X as age):H=-0.26X²+1.4338X+0.80936,D=0.01057X²+1.5977X-0.06318,W=0.00315X²+0.03525X+0.09871,and their fitting correlation coefficients respectively 0.8313,0.9788 and 0.9971.Toona sinensis biomass and carbon storage dynamics change process were divided into three stages.At the age of 1 to 10 Toona sinensis juvenile forest' biomass and carbon stock slowly rose,at the age of 11 to 20 forest biological amount and carbon storage was in a medium speed rise,at the age of 21 to 30,mature forest biomass and carbon storage was in the period of rapid rise.Therefore,this paper put forward reasonable stand density carbon sink function of Toona sinensis plantation,Toona sinensis in the juvenile stage in accordance with the initial planting density of 1 666 trees per hectare should be cultivated,at the toona fast-growing stage the thinning density should concerved at 405 trees per hectare,in Toona sinensis mature period,the thinning density preservation at 240 trees per hectare was appropriate,aiming to provide the basis for the data analysis of the research for the function of carbon sequestration and forest plantations community management.