Abstract: In order to investigate the mutual feedback effects of rill morphology evolution on runoff and sediment, variation characteristics of runoff and sediment during the evolution of rill morphology were studied. In the current work, an indoor soil bin rainfall simulation experiment was performed using a 3-D terrain scanning method. Loessial soil was analyzed under rainfall intensities of 66 mm/h, 94 mm/h, and 127 mm/h. Results showed that the evolution of rill morphology had a profound effect on sediment yield, but the impact on runoff was not obvious. The variation in runoff depended mainly on infiltration conditions and crust effect of soil and patterns of runoff production. The runoff production on the slope had a tendency to first increase and then decrease before finally reaching stability. There was an obvious relationship between rill morphology evolution and sediment yield; the correlation coefficients of geomorphologic comentropy and soil loss with erosion rate were 0.954 and 0.916, respectively. The emergence of rills was found to aggravate the erosion, resulting in a significant increase in sediment concentration. The variation in sediment yield in rainfall of different intensities was basically the same. The more intense the rainfall, the higher sediment concentration after the rill network became stable.