根据以往的研究,应用力学原理提出了能量抗冲指标,避免了研究同一冲样抗冲性受雨强、坡度等因素影响的可变性,增强了研究对象的可比性。研究表明,参试枯落物的抗冲能力随其厚度递增,其中油松、山杨、沙棘、刺槐这些枯落物层下的土壤抗冲能力也与其自身抗冲性一致。枯落物能减轻土壤冲失主要是由于它能降低径流速度。当有0.5cm枯落物层时,可降低径流速度80％～90％。 According to the previous research, the energy impact index is put forward based on the principle of mechanics, which avoids the study of the variability of impact resistance of the same sample by rainfall intensity, slope and other factors, and enhances the comparability of the research object. The results showed that the impact abilities of litters increased with the thickness of the litter, and the soil anti-scourability under the litter layer of Pinus tabulaeformis, aspen, Seabuckthorn and Robinia pseudoacacia was also consistent with its own anti-scour ability. Litter can reduce soil erosion mainly because it reduces runoff velocity. When 0.5cm litter layer, can reduce the runoff speed of 80% to 90%.