Sediment sorting of debris flow affects the kinetic and dynamic characteristics such as erosion along the distance, movement distance and impact force. A better understanding of sediment sorting will improve research of control engineering and sensitivity division. 105 experiments were conducted to study the effect of material composition, flow and gradient on sediment sorting of debris flow head with artificial preparation of sand. The results showed that the sediment sorting increases firstly and decreases secondly as the increase of content of sand grain or gradient or flow. In order to consider the influence of each factor, sorting ratio (R) was defined as the function of stream power and underwater gravity of sediment. As increasing, sediment sorting of debris flow head increases firstly, decreases then. Finally, the model of sediments sorting of debris flow was established and validated.
