There are much vegetation in a river bank Vegetation has a role of protecting banks as good. On the other hand, it has a bad role of being rose the water level.So, we should make a river course planning which is desirable for both of the river environment and flood control by using vegetation.
In this paper, vegetation is attempted to use as a groin. It is experimented by a curved channel withmovable bed and investigated the flow and bed topography around the vegetation groin, and considered about the possibility of vegetation use as a groin.