[Objective] The law of sediment yield in a karst trough valley was studied to provide a theoretical basis for the prevention and control of soil and water loss on the slope of the trough area.[Methods] Based on the runoff plots of Zhongliang Mountain at Beibei District of Chongqing City, the effects of land use types (cultivated land, woodland, orchard, and bamboo forest land), rainfall grade, and rainfall characteristics on runoff and sediment yield on slopes were investigated.[Results] ① The total runoff of the four runoff plots was as follows:cultivated land (35.35 mm), followed by orchard land (31.51 mm), bamboo forest land (23.47 mm), and forest (19.57 mm). The runoff coefficient of them (3.12%~0.5.70%) was much lower than that of the nonkarst area (approximately 20%). The slope sediment yield of the four land uses decreased orderly, and that of the cultivated land was the largest (3.37 kg), followed by orchards (2.60 kg), forest (1.60 kg), and bamboo forest (1.43 kg). ② Although rainstorm accounted for 1.53% of the total rainfall, the runoff and sediment yield accounted for 42.28% and 33.42%, respectively. Moderate rain accounted for 16.61% of the total annual runoff, and sediment yield accounted for 20.47% of the total annual sediment yield. However, because of the frequent rainfall of moderate rain, the sediment loss caused by it can not be ignored. ③ Rainfall had the greatest impact on the runoff on slopes under different land uses. Moreover, I₃₀ had the greatest impact on the sediment yield of cultivated land and orchards, and rainfall had the greatest impact on the sediment yield of forest land and orchards.[Conclusion] Under the same rainfall conditions, the runoff and sediment yield of cultivated land are the largest, followed by those of orchards. Under certain slope conditions, different levels of rainfall are the main factors affecting runoff and sediment yield. Therefore, when arranging agricultural activities, it is necessary to avoid high-intensity rainfall to reduce the occurrence of serious erosion events.