Abstract:With the biomass data of Larix olgensis plantations of 8-56 years, we built the organic biomass model, and discussed the distribution and change rules of biomass in bole, bark, branches, leaves and root as well as the carbon storage capacity of tree layer. The organic biomass of individual wood and stand had a certain trend to increase with the increase of forest age, the biomass of individual wood increased from 0.714 kg in 8 years to 328.196 kg in 56 years, and the biomass increased from 0.519 t·hm-2 in 8 years to 251.39 t·hm-2 in 56 years. The trunk took the largest percentage and amplification. The average carbon storage of individual wood was 74.822 kg, the carbon density of stand in 56 years was 130.455 t·hm-2 with the average value of 63.113 t·hm-2, and the carbon storage in each organ had obvious change rule. The average annual carbon storage of juvenile, middle-aged, near-mature and mature stand were 0.087, 1.193, 1.703 and 2.124 t·hm-2, respectively. The average annual growth rate order from big to small is middle-aged stand, juvenile stand, mature stand and nearmature stand. Therefore, the organic biomass of individual wood and stand of L.olgensis plantations has an obvious change rule with the increasing of forest age, the mature stand has the highest carbon storage level, and the middle-aged stand has the largest potential carbon storage ability.