Abstract: Engineering deposits have unique soil constitutions and complex conditions of their surface layers that are quite different from those of a regular soil slope. Hydrodynamic mechanisms established through previous studies of the traditional slopes, are not applicable for such deposits with three-dimensional shapes and it is necessary to study the hydrodynamic process of soil erosion on the engineering deposits. In this study, we have conducted laboratory experiments of rainfall erosion on a special type of engineering deposits? roller compacted by construction machinery on the top platform of the slope, focusing on the hydrodynamic process of erosion in the conditions of four artificial rainfall intensities (1.0, 1.5, 2.0 and 2.5 mm/min) and three gravel contents (10%, 20% and 30%). The results show that the soil detachment rate is a linear function of rainfall intensity and percentage gravel mass content with a squared correlation coefficient of R2=0.919. Thus, the sediment yield can be predicted if these two parameters are known. Hydraulic parameters such as flow shear stress, stream power, unit stream power, and the specific energy of flow cross section, could also be used for calculation of the detachment rate. Among them, the stream power is the most suitable parameter and is highly correlated with the detachment rate (R2 = 0.884). This indicates that the effect of water flow on the deposits tested in this study is better described in terms of its energy than its stress. A comparison reveals that for the deposits tested, both their top platform part and slope part contribute to the total detachment rate. The contribution by the former, which is 5.0×10-6 kg/(m2?s) for the experimental condition, depends primarily on the area of the top platform compacted.