Soil organic carbon(SOC), organic carbon density and organic carbon storage were analyzed in 15plots soil profiles in Diaoluoshan Natural Reserve(DNR) of Hainan Island, to discover its soil organic carbon distribution characteristic, as well to preliminarily estimate soil organic carbon storage in DNR. Results showed that:(1) The vertical distribution of soil organic carbon concentration and density generally decreased with soil depth. The average organic carbon concentration and density were 16.86 g/kg and 15.31 kg/m2.(2) The organic carbon concentration in different places of same layer had significant difference, which mainly appeared in soil surface and gradually getting smaller with soil depth.(3) There was significantly negative correlation between soil organic carbon concentration and soil depth, the best fitting curve model was a power function, the regression equation was y=113.796x-0.6, and the correlation coefficient was 0.836.(4) The total organic carbon storage in the soil layer 0-100 cm of DNR was around 2.816 4 million ton, and the proportion of soil organic carbon storage in soil surface was minor difference to global average level.