Labile organic carbon( LOC) is the most active part of soil organic carbon,and it is more sensitive to environment change. This paper studied the effect of soil erosion on LOC with field run off??plot observation and laboratory analysis.Results show that the LOC content in soil ranged between 0.15 g/ kg and 0.34 g/ kg, and was between 0.28 g/ kg and 2.92 g/ kg in sediment.For a slope gradient less than 20,the amount of LOC loss in creased with increased slope gradient.The enrichment ratio of LOC ranged between 3.25 and 8.47,and was negatively related to erosion rate and slope gradient.The LOC content in sediment decreased prog ressively as a log arithm function with increased soil erosion rate,and the LOC loss degree linearly increased with increased soil erosion rate.