Abstract: The main site factors which enfluence the evaluations of site quality,including flow degree, position and size of sandhill, and nonsite factorsincluding age, density and cuting, are selected out by taking biomass (aboveground) as the index of evaluating site quality of shrub forest. The quantitative mathematic model is establishedd by converting qualitative data to quantitative data as the independent variable, and biomass to be the dependentvariable, by which quantitative tables for 9 shrub species, such as Caraganaintermedia, C.korshinskii, Hedysarum scoparium, H. lacve, Salix psammophila, Amorpha fruticosa, Hippophae rhamnoides, Artemisia sphaerocephala, A.ordosica, are drawn up. The correlation coefficient, surplus standard error, aswell as other indexes are adequate to demands. On the bases of the tables,the biomass of various shrub growing in the same type of site can be evaluatedcomprehensively so that the shrub species can be matched with the sites. Thecrown breadth and height of shrub reflect the boimass yield above ground,the multiple regression mathematic model can be established, which providesa simple method for evaluating the shrub biomass in the forest land.

Key words: Biomass, Quantification of site quality