[Objective] Spatial distribution of aboveground biomass and its relationship with environmental factors were studied in desert grassland in the middle part of Hexi Corridor to provide a reliable data for the assessment of grassland ecosystem carbon stock, and to illustrate its change at regional scale. [Methods] The present study, based on a total of 52 sampling sites in desert grasslands in the middle region of Hexi Corridors, illustrated the regional distribution pattern of aboveground biomass and its response to environmental factors were investigated. [Results] The results showed that aboveground biomass of desert grasslands ranged from 11.17~523.76 g/m², with an average of 149.67 g/m², and increased from the southeast to the northwest in the survey area. There were 15 communities with dominant species appeared in these 52 sampling. Average aboveground biomasses of Lycium ruthenicum and Scorzonera divaricate community were 49.88±7.42 g/m² and 201.69±98.48 g/m², respectively, which were also the minimum and maximum of aboveground biomass among the 15 communities. Aboveground biomass was significantly and negatively correlated with longitude, and was significantly and positively correlated with elevation. 39.8% of the spatial variation of aboveground biomass can be interpreted by soil factors. Among which, soil type, soil bulk density and soil organic matter were significantly affected aboveground biomass distribution of desert grassland, while the effects of soil moisture on aboveground biomass was weak. [Conclusion] Aboveground biomass in desert grassland of Hexi Corridor increased from the southeast to the northwest. Altitude and soil environmental factors are the key factors affecting the distribution pattern.