In the experiment, by taking Quercus engleriana Seem., Betula albo- sinensis Burk., Abies faxoniana Rehd. and Fargesia rufa Yi, in the vegetation restoration pattern area of Beichuan Nature Reserve as the research objects, the study on the biomass models, the biomass distribution law of single plant and the growth rule of every organ of the four tree species was made. The results indicated that in the compositions of all of the species, the proportion of trunk biomass was the highest, while that of trunk biomass was the lowest, the proportions of branch and root biomasses varied depending on species; in the comparison of correlativity between the proportions of biomasses of all nutrition organs and biomass of single plant, the relations were generally significant, the tree trunks were positively related while the roots were negatively related; the proportion of trunk biomass of all species was significantly and negatively related to the proportions of leaf and branch biomasses, while the biomass of leaves was significantly and positively related to the biomass of branches.
