Abstract:Taking Larix gmelini as an example,the consociation equation set model method was used in creating duality standing tree volume model, the variance of constructing model and estimation precondition could be effectively solved to duality standing tree volume model. The usual nonlinear estimation and two steps estimations method were used to estimate the consociation equation set model method of duality standing tree volume model. As a result, the model could be estimated by two methods; two steps estimation method could reduce system error, and attain error limit than universal model, two steps estimation method was better than usual nonlinear estimation.