Rare earth element (REE) tracing method is a new method to study soil erosions. It is widely used in the studying of the laws of erosion vertical distribution on land slope due to its accuracy. Based on the reviewing of the REE(Rare Earth Element) trace method and the present application of the method to the study of soil erosion. The tracing and INAA technology, the calculation of the erosion results, as well as its application in the soil erosion on slope were introduced. Combined with the runoff scouring method under the different slope gradients, different flow discharges and REE(Rare Earth Element) technology, the temporal and spatial variation rules of the sediment yield on the land slope were studied in this paper. The results showed that the relative erosion mass of the different section along the slope decreases at the beginning and increases at the later period. Experiments on the steeper slope with a smaller flow discharge indicated that the relative erosion mass of the different section along the slope is similar to that on the gentle slope. With the larger flow discharge, the relative erosion mass decreases with an increase in the length of slope. The temporal variation of sediment yield on the slope is that the relative erosion mass at the bottom section of the slope decreases with experimental time increase, while the relative erosion mass on other section increases fluctuantly.