Abstract: Height and coverag of Aneurolepidium chinense community had a good correlation with its biomass above ground(R= 0.9316). A multivariate regression equation was established for estimating aboveground biomass of the community. Data of spectral reflectance for simulated band3(0.63—0.69 um) and 4 (0.76—0.90um) of thematic mapper or landsat4or5,were collected with a handheld radiometer in three principal grassland plant communities (Aneurolepidium chinense community ,Aneurolepidium chinense + forbs community and Stipa baicalensis community)during plant growing seasons in 1988.The study showed that vegetation index(VI)had the best exponential correlationship with aboveground biomass in comparison with that of IR or IR/R for each of the communities. Therefore, with change of the growing seasons nine different spectral models related to VI for estimating aboveground biomass of the communities were established.