Abstract: The plant species and biomass were investigated in desertification land in Rangtang county of Northwest Sichuan.The results showed that 10 families and 24 species of plants were found in control grassland species,12 families and 23 species of plants were found in desertification land,12 families and 15 species of herbal plants and 4 families and 5 shrub species were found in exposed sandy land,14 families and 19 species were found in fixed sandy land.Along with the severity of desertification,the number of species reduced,and families increased.Besides,total biomass,above-ground and below-ground biomass firstly increased,then decreased.The order of the Shannon-Wiener diversity and the Margalef richness index was followed as:control land > desertification land > fixed sandy land > exposed sandy land (herb) > exposed sandy land (shrub).The order of uniformity index was exposed sand (herb) > control land > fixed sandy land > exposed Sandy land (shrub) > desertification land.