Development of single-tree biomass model can provide sound basis for the evaluation of forest productivity and forest quality,and monitoring forest carbon sequestration ability.To make the sum of estimated values from biomass models of various components of tree (i.e.stem wood,branches,foliage,stem bark,root) equal to the estimated value of tree total biomass model and make volume compatible to biomass,both independent biomass models of various components and two sets of single-tree compatible biomass models were separately built for Quercus variabilis Blume (cork oak) plantation and natural forests in North China.107 plots with an area of 0.4 ha were investigated.100 trees were felled to measure fresh weight of different overground components.19 trees were dug to get both root fresh weight and overground fresh weight.Allometric equation and method of Nonlinearity Error Variable Simultaneous Equations were used to build models.And methods of ordinary Least Squares (OLS) and two-stage least squares were used to estimate parameters of the models.Those biomass models in this study were tested to have high prediction accuracies.The two sets of compatible biomass models can be used for the calculation and prediction of biomass or carbon stocks of the cork oak forests in North China.In addition,the modeling approach and process used in this study have good versatility and promotion.