Biomass is one of the important items for today ,s regional forest resources inventory and monitoring. However, the current biomass models have two big problems,that is,the biomass estimator is not compatible with the volume estimator,and total biomass estimator is not compatible with the biomass estimators of stem,branch, beaf etc. In present paper,a new compatible tree biomass model system for Chinese fir was presented based on volume being selected as explanatory variable and two or more simultaneous models being estimated dependently. These new models could solve the two problems above and have higher precision and better applicability than the currently-used biomass models.