Based on the 1:1 000 000 scale soil database of the Qinghai-Tibet Plateau,the data from the second national soil survey and the data measured by the author,soil organic carbon storages and densities in the organic horizon, mineral horizon,and whole profile of the soil in the Qinghai-Tibet Plateau were estimated.It was shown that the average soil organic carbon density was estimated around C 7.2 kg m^-2,a little lower compared with the national average soil organic carbon density,C 8.01～19.05 kg m^-2 obtained by the previous researches,and the soil organic carbon storage about 18.37 Pg,of which 38.14% was stored in the organic horizon,and 61.86% in the mineral horizon.