To quicken the recovery of vegetation and to dissolve a landslide scar by constructing a dam with effects of damming collapsing sediment and quickening the growth of plants in a valley of the landslide scar.

The dam is constructed from a slope on one side of the valley of the landslide scar to the oblique upstream direction of the valley. Also, the dam is structured to gradually lower the height as turning to the oblique upstream direction. Thus, in a place near the base part of the dam on the downstream side, movement of the sediment in the case that the scale of a landslide is not big or when rain falls is reduced. Thus, plants start to grow from the place and the growth then spreads to the entire dam and the entire landslide scar.