【Objective】 During the processes of production and construction in Guanzhong Region, a large number of stacks of Lou soil were formed. Gravel in the stack is an important factor affecting soil erosion on stack slopes in characteristic. Therefore, this study was designed to explore impacts of gravel concentration on runoff and sediment yielding processes on slopes of Lou soil stacks different in gravel content.【Method】In this paper, artificial rainfalls were simulated indoor, different in intensity (1.0 mm?min-1, 1.5 mm?min-1, 2.0 mm?min-1 and 2.5 mm?min-1), to explore their effects on runoff and sediment yield on slopes of Lou soil stacks different in gravel content (0, 10%, 20% and 30%). The experiment had test plots set up, 5 m×1 m×0.6 m in area and 25° in slope gradient. The nozzles of the artificial rainfall simulator were 18 m high over the slopes, spraying water evenly (more than 80% in evenness). Rainfall intensity were calibrated before the start of each test to ensure that the deviation of the actual rainfall intensity in the test was kept less than 5% of the designed rain intensity for the test. During the test, flow velocity of the runoff on the slope was measured with the dyeing method, width of the flow with a steel ruler, duration of runoff and sediment collection recorded with a stopwatch, and quantity of the samples weighed on an electronic scale. 【Result】 Results show: (1) runoff lasted the longest on the Lou soil slope 10% in gravel content under rainfall 1.0 mm?min-1 in intensity, and the shortest under rainfall lower than 1.0 mm?min-1 in intensity; (2) mean flow velocity of runoff increased with rising rainfall intensity on all the gravel-containing slopes regardless of gravel content. The flow velocity on the slope 10% in gravel content was the highest under rainfalls 1.0 and 2.5 mm?min-1 in intensity, and 15.3%～21.2% and 13.6%～14.1% lower than that on the slope under rainfall 1.5 and 2.0 mm?min-1 in intensity, respectively; (3) sediment content in runoff dropped drastically during the initial period (0～6 min) of each rainfall, regardless of rainfall intensity on all the gravel-containing slopes, and 6 min later, it gradually leveled off under the rainfalls 1.0 and 1.5 mm?min-1 in intensity, and fluctuated sharply under the rainfalls 2.0 and 2.5 mm?min-1 in intensity. During this period gravels dominated the process of sediment yield; (4) the amount of erosion per rainfall event showed a significant power function relationship with rainfall intensity, and decreased by 22.4%～42.6%, 8.2%～66.3%, 2.2%～56.5% and 45.0%～68.3%, on the gravel containing slopes under rainfall 1.0 mm.min-1, 1.5 mm.min-1, 2.0 mm.min-1 and 2.5 mm.min-1 in intensity, respectively as compared with that on the pure soil slope. 【Conclusion】This study may serve as a theoretical basis for establishment of a model for research on water erosion on slopes of soil stacks in the Guanzhong Region .