Landslide accumulations in the earthquake area of Wenchuan are formed typically of mixtures of rock fragments and soil, loose in structure. Drastic rill or gully erosion tends to occur with rainfall runoff, thus leading to grave soil and water loss. Therefore it is of great importance to launch a study on rules of water and sediment transport with runoff on landslide accumulation slopes. Based on field investigation, an indoor scouring experiment, designed to have 4 treatments in rock fragment and soil ratio (0:1, 1:3, 1:2 and 1:1), 3 treatments in water flow rate (4, 8 and 12 L min^-1) and 2 treatments in nearest dwell angle (34° and 36°) was carried out to study variations of soil erosion rate and hydrodynamic parameters and their relationships on landslide accumulation slopes in the Wenchuan earthquake area. Results show that with the souring experiment going on, the soil erosion rate, flowing power and specific flowing power gradually decreased, while water flow shear force increased at first then decreased, and specific energy at water flow cross-section decreased at first, then increased and decreased at last. On slopes, 0:1, 1:3 and 1:1 in rock/soil ratio, soil erosion rate, water flow shear force, flowing power, and specific energy at water flow cross-section, increased with increasing water flow rate, but on slopes, 1:2 in rock/soil ratio, only soil erosion rate increased with increasing water flow rate and the other indices varied irregularly. In this study, the effects of water flow shear force, flowing power and specific energy at water flow cross-section on soil erosion rate could all be described with power function equations, and the effect of specific flowing power was not so obvious. All the findings in this study may help lay down a foundation for establishment of a model for predicting soil erosion on landslide accumulation slopes in the earthquake areas of Wenchuan.