In this study

simulated rainfall was conducted to mainly investigate and analyze organic carbon content of sediment and its dynamic change during the rainfall on the outdoor runoff plot under random conditions. The sediment organic carbon content

which was significantly higher than that of the soil organic carbon (p＜0.01)

decreased gradually during the early stage of the rainfall

then tended to be stable in the later stage. The organic carbon was obviously enriched in sediment

and the maximum of enrichment ratio was 1.780. The content and enrichment ratio of organic carbon in sediment decreased obviously with the increasing of erosion rate

and tended to be stable. The loss process of sediment organic carbon showed a unimodal distribution during the rainfall

which increased first with the rainfall

then decreased after reaching the maximum value

and finally tended to quasi stable. There was a significant linear relationship between soil organic carbon loss and soil erosion amount (p＜0.01)

indicating that soil erosion amount determined the organic carbon loss during the erosion process

so accurate estimation of soil erosion intensity was the basis of estimating organic carbon loss on the slope.