A methodology was developed for estimating wide area above ground biomass (AB) in the Xilingol steppe. Inner Mongolian Autonomous of China, using Advanced Very High Resolution Radiometer (AVHRR) data, which is characterized by frequent observations and low spatial resolution, onboard a National Oceanic and Atmospheric Administration (NOAA) satellite. Twenty widely separated homogeneous grassland sites were selected by field survey and by investigating past Landsat TM images. Among the selected sites, ABs were regressed onto Normalized Difference Vegetation Indices (NDVI) derived from the NOAA/AVHRR data. Selected fields included 6 Meadow steppe sites, 13 Typical steppe sites and one Desert steppe site. In order to coordinate with NOAA pixels, the aboveground parts of the vegetation of each of 9 quadrats (1m×1m) set up 700m apart, were examined and clipped to measure the dry weight. Relationships between steppe biomass and NDVI values for all 20 sites showed a strong positive correlation (r=0.62 : P<0.01). Results from statistical analysis indicated that 5 quadrats instead of 9 were sufficient for obtaining a satisfactory coefficient. By applying this relationship, the mean AB of the entire Xilingol steppe for summer 2001 was estimated as 1,189 kg/ha. It demonstrates the decrease in steppe biomass during the last 14 years. In addition, it suggests that, in estimating AB using different equations for Meadow steppe and Typical steppe, a high accuracy (r=0.90, P<0.0001) can be obtained.