Forest biomass study takes great sense in estimation of carbon release which is an important in increasement of carbon dioxide. There are many models to estimate forest biomass by the volume data, among them allometric equations iswidely studied and highly recommended. The paper proposed a new model B ï½ cV d (B stands for aboveground biomass, V for forest volume, c and d for parameters of the new models) to estimate the aboveground biomass (AGB) by the allometric equations and the Squrr Equation, followed the assumption of the new model, a set of new equations to estimate forest biomass in a sample plot can be drew. In order to prove the newmodel is superior to traditional ones in converting volume to biomass, the experiments were carried out in Dangchuang forest farm, Gan Su province in China, 32 trees ofQuercus aliena Var. cuteserata were fell,measured the volume andAGB, fitted by two tranditionalmodels and the new one then did a comparison. The results showed that new model was better and the relationship between the AGB and tree volume is exponential not linearity. In practical, the volume can be estimated by Squrr Equation, also by theYamamoto formula andHerschel formula.And the volume estimated by these theoretical equationswhich includes Squrr Equation,Yamamoto formula and Herschel formula can be used to estimate AGB.