HJ 1A/1B satellite data in 2010 were used to extract wetland vegetation of East Dongting Lake. Based on the same period's MODIS13 (Moderate Resolution Imaging Spectrometer) data production, the annual maximum value and average value of the EVI (Enhanced Vegetation Index) were synthesized. Vegetation spatial distribution and its biomass were discussed by combining the above indexes with the elevation figure of East Dongting Lake. Moreover, the most suitable growth area of vegetation was assessed from hydrological factors and vegetation growth characteristics, which will provide theoretical guidance for the protection of the vegetation diversity and the restoration and utilization of the vegetation resource in East Dongting Lake. All these proved that long water flooded time in the regions of low elevation was harmful to the growth of moss grasses. The results indicated that vegetation spatial distribution and its biomass had great correlation with the elevation and water environment in East Dongting. The shelter forests, whose water demand is not high, grow in the area more than 30m in height and away from the water, while reeds grow well in the area above 27m elevation and near waters, and moss grasses are suitable to grow in the regions ranging from 23m to 27 m.