Mountain rivers are very steep and sediment transportation occurs frequently. It is very difficult to prevent natural disaster on natural mountain rivers, whose forms tend to change. Therefore river works which had an impact on the environment, for example channel work, have been constructed. But mountain rivers have many pools, riffle and ecological variety. So we believe we can restore, rehabilitate and protect the river eco-system by using natural hydraulics features of mountain rivers. This report describes classification of habitat by longitudinal section. And it also describes relation between medium-scale bedforms.