Abstract
A lot of forest-biomass exists on the steep mountain in Japan. However, it is very difficult to obtain the forest-biomass like brushwood, from the deep mountain to human habitation. Using by chute, brushwood can be transported automatically if we can keep an appropriate slope gradient. The most important point is a repose angle of chip on the slope. These angles are strongly depending on the figure of chip, the aspect ratio, and the surface roughness of the chute bed.