There are more literatures related to sheet erosion on the loess sloping and sand loess soil sloping, but there are little information on sheet erosion on the clay loess sloping. Therefore, the purpose of this study was to investigate effects of rainfall intensity and slope gradient on sheet erosion at the clay loess sloping by using simulated fainfall. The experiment treatment included two rainfall intensities (90 mm/h and 120 mm/h) and four slope gradients (10°, 15°, 20° and 25°). The results showed that under the same rainfall, effects of rainfall intensity and slope gradient on runoff rate had no significant difference; while both of them on sheet erosion had significant difference. Under the same slope gradient, when rainfall intensity increased from 90 mm/h to 120 mm/h, the sheet erosion increased 76.2%—128.0%. As slope gradient changed from 10° to 25° under both of 90 and 120 mm/h, the sheet erosion increased 29.3%—72.1% and 1.8%—75.4%, respectively. Under the same rainfall duration, when rainfall intensity increased from 90 mm/h to 120 mm/h, the runoff rate and sheet erosion increased 19.5%—26.0% and 103.8%—162.2%, respectively. A slope gradient shifted from 10° to 25°, the sheet erosion under the both of 90 mm/h and 120 mm/h increased 25.1%—67.4% and 1.8%—75.0%, respectively. The relative contribution of rainfall intensity to stable-stage sheet erosion rate was above 82%, which was much higher than that of slope gradient.