In order to assess the effect of grazing on grasslands using floristic composition, we studied the floristic composition and plant biomass of steppe vegetation in Hulunbeier, Inner Mongolia. The dominant species of the grasslands were Stipa krylovii, Stipa grandis and Leymus chinensis. Floristic composition changed according to grazing pressure, being light, heavy and moderate. Under heavy grazing conditions, the importance value of P. acaulis, C. korshinskyi and Cleistogenes squarrosa increased in the plant community. These species were indicators of heavily grazed stand. Plant biomass of the stands ranged within 11.6g $m^{-2}$ and 63.5g $m^{-2}$ and 69.5g $m^{-2}$ and 166.2g $m^{-2}$ to the west and east of Lake Hulun, respectively. These values are equivalent to ca. $450{sim}1,000kg$ of atmospheric carbon per hector, which is retained within the stand during the summer season.