Debris flow can be regenerated as the soil materials deposit enough in the valley and the rainfall is strong enough. Therefore, the soil materials which contain with coarse and fine granulars, will be carried out and deposit on the low land to form an alluvial fan. As to the progression of alluvial fan which is caused by debris flow, is concerned as an important factor for preventing from the damage of debris flow. Therefore, this paper is going to study the sequent deposition of debris flow in order to know the progression of debris-flow fan. The experiment was conducted with a flume in laboratory. And three different slopes and three different debris-flow discharges were used to observe the sequent deposition with the same scale of debris flow.