【Objective】The differences in soil detachment and transport mechanisms between interrill and rill erosion lead to the differences in organic carbon loss by interrill and rill erosion. However, few studies were conducted to explore the effects and contributions of interrill and rill erosion on organic carbon loss during the erosion process because of the limitation of research methods. Successful use of the radionuclide 7Be to document soil erosion provides a means of addressing this need. The objectives of this study were to first estimate the contribution of interrill and rill erosion to sediment yield and then quantitatively explore the effects and contributions of interrill and rill erosion on organic carbon loss on the loess slope. 【Method】The simulated rainfall experiments with five slope gradients (5°, 10°, 15°, 20°, 25°and 30°) were conducted under different rainfall intensities in the field to investigate soil and organic carbon loss and 7Be tracing technology was used to quantify the contribution rate of interrill and rill erosion on sediment yield and organic carbon loss for the loess slope.【Result】Interrill erosion is the main and the relative contribution of interrill erosion on sediment yield was 86% on the 5°plot. But rill erosion dominated on the plots with gradient greater than 5°. The relative contribution of rill erosion on sediment yield ranged from 61% to 71% and could even reach 96% during the rainfall. The average enrichment ratio of organic carbon of sediment from the entire plot and the interrill area was 1.16±0.15 and 1.50±0.50, respectively, during the rainfall. The enrichment could increase organic carbon loss rate of 0.008 to 0.028 g m-2 min-1. The relative contribution of rill erosion to organic carbon loss were between 55% and 62% on plots with gradient greater than 5°, which were lower than those of rill erosion to sediment production, but still dominated. Sediment yield from the entire plot and the interrill area could respectively explain 97% and 89% of the variations of organic carbon loss from the entire plot and the interrill area. 【Conclusion】The organic carbon enrichment ratio had less effects on organic carbon loss when rill erosion occurred severely. Sediment yield determined the amount of organic carbon loss. Severe rill erosion could enhance the enrichment ratio of organic carbon of sediment from the interrill area.