Abstract: This paper describes the spectral reflectance characteristics of herbaceous vegetation of grassland of Xilin Gol, Inner Mongolia and analyzes the correlation between reflectance of different band and yield of grassland. Some models for grassland yield estimation have been made using six different kinds of ratio-indexes or perpendicular indexes of vegetation. The accuracy of every model has been tested. It was found that G. ND and PVI may successfully be used for yield estimation of grassland with error less than 10%.