Randomly sampling saplings with D 1.3≤2.5 cm for 14 species in the Changbaishan Mountains region of northeastern China, we established and validated organs and whole plant biomass models for each of the 14 species. It was found that sapling organs and whole plant biomass can be modeled accurately by the power function when ground diameter (D0) or the product of ground diameter and height (D20H) taken as the independent variables. The correlation coefficient R2 ranged between 0.712 and 0.983 and SEE(standard error of the estimate) was lower (0.217-1.122). With respect to estimation accuracy and taking R2 as the fitting statistics, sapling organs and whole plant biomass models were in the following descending accuracy order：whole plant biomassaboveground biomassbranch biomassunderground biomassleaf biomass. It is validated that the fitted models can give accurate estimates for sapling organs and plant biomass when ground diameter taken as the independent variable. However, using the product of ground diameter and height as the independent variable, the fitted models yield accurate estimates only for 8 species saplings such as Amorpha fruticosa, Acer mandshuricum, etc., but not for some organs or whole plant biomass for the other 6 species，such as Pinus koraiensis and Acer triflorum，etc.