Abstract: Soil detachment is one of the most important components of soil erosion process. A precise prediction of this component is significant to the development of physical based erosion model. In this paper, the relationship between soil detachment rate and slope, flow rate, shear stress, stream power and unit stream power was discussed. The experimental results showed that soil detachment rates would be predicted by a linear function of flow rate and slope. Soil detachment does not occur until flow reaches a critical rate. Among shear stress, stream power and unit stream power, stream power is best related to soil detachment rate. Compared with stream power model, slope-flow rate model is more applicable and easier to operate.