Abstract: Carbon storage capacity is the key factor to estimate the quantity of carbon emissions and sequestrations by terrestrial ecosystem. As one of the important indicators，carbon density has vital significance in determining carbon sinks and developing reasonable policies for global change mitigation.  Arid and semiarid area is widely distributed in Central Asia，however，research on carbon storage in this region is comparably scarce. This paper investigates vegetation and soil carbon density in arid region of Central Asia，based on published literatures associated to biomass or vegetation carbon density and soil profile data of the five countries in Central Asia and Xinjiang，China. The results shows that vegetation and soil carbon density present certain differences with different regions and vegetation types in the arid region of Central Asia. In the arid region of Central Asia，the woodland has the highest vegetation carbon density and soil organic carbon density because of the best hydrothermal conditions. The vegetation and soil carbon density of woodland in Xinjiang are 7 728.1 g C/m² and 25.4 kg C/m² respectively，which are higher than that in other five countries of Central Asia （6 236.0 g C/m² and 21.6 kg C/m² respectively）. The soil carbon density of grassland is higher than the farmland’s in arid region of Central Asia. Among them，the soil carbon density of grassland in Xinjiang and five countries of Central Asia are 15.4 kg C/m² and 10.9 kg C/m²，and the soil carbon density of farmland are 9.5 kg C/m² and 7.1 kg C/m² respectively，because of anthropology disturbance. The vegetation carbon density of grassland in Xinjiang and five countries of Central Asia are 585.5 g C/m² and 645.9 g C/m²，which is lower than the vegetation carbon density of farmland in Xinjiang（806.0 g C/m²），but higher than the vegetation carbon density of farmland in five countries of Central Asia（384.7 g C/m²），which is dominated by dry farmland with outdated farming system. Bare land has the lowest vegetation and soil carbon density in the whole study area due to the lowest vegetation coverage. The vegetation carbon density of bare land in Xinjiang and five countries in Central Asia are 54.6 g C/m² and 86.3 g C/m²，and the soil carbon density of bare land are 2.80 kg C/m² and 2.6 kg C/m². In addition，in the arid region of Central Asia，vegetation and soil carbon density display certain vertical variation characteristics because of the precipitation and temperature are affect by the elevation. Overall，terrestrial ecosystem carbon storage capacity is higher in Xinjiang than in the five countries of Central Asia.

Key words: vegetation, soil, carbon density, arid region, Central Asia