There are close relations between the development of Loess Plateau and breaking-off of Yellow River.In this paper,based on rainfall experiments of Lou soil,the variation trends of infiltration supplement coefficient to rainfall were analyzed,the time variation trends of sediment content in runoff and the cumulative sediment content were compared at different rainfall intensities,furthermore,the erosion data was connected with infiltration characteristics to discuss their relations observed at the same time.The results showed: the infiltration supplement coefficient of rainfall decreased when the rainfall intensity increased,the smaller the rainfall intensity,the larger the rainfall infiltration supplement coefficients,and the linear functions were fitted well to them;at the beginning of rainfall,the biggest value of sediment content existed,but its variation trends became flat within 10 minutes of sediment producing.The larger the rainfall intensities,the larger the initial and steady sediment contents,but their total variation trends differs little.Moreover,there are similar trends of sediment distribution curve and infiltration ratio curve;good power functions was fitted for cumulative sediment content and rainfall time at different rainfall intensities,and the exponential part increased when the rainfall intensities increased.The variation trends of infiltration ratios differed with that of cumulative sediment content,when the cumulative sediment content increased,the corresponding infiltration rate decreased,their variation trends was obvious when the rainfall intensities increased.