【Objective】We aimed to simulate the stand growth and biomass changes of Larix olgensis plantations with forest management under climate change. 【Method】Fifteen permanent sample plots of L. olgensis plantations located at Helong, Shulan,Tonghua,Wangqing and Changchun,Jilin Province,were selected to simulate stand biomass and its allocation by integrating 3-PG model with climate,soil and stand growth observations. Moreover,the effect of elevated CO_2 concentration on biomass allocation was simulated. 【Result】With the exception of leaf biomass (R~2 = 0.39),the 3-PG model could well simulate the trend of volume and stem biomass,with R~2 between predicted and observed values ranging from 0.62 to 0.86. In addition,both the mean relative errors and the relative root mean square errors were less than 15%. Parameter sensitivity analysis showed that the soil fertility rating and biomass allocation are the key parameters of the model. In addition,we found that the biomass allocation increased with increasing CO_2 concentrations. 【Conclusion】 Therefore,the 3-PG model can be used to simulate the growth of L. olgensis plantations.