Abstract: The turbulent characteristics of flow in vegetated channels are studied in physical model tests.Test results show that the roughness of floodplain and turbulence of flow increase after flexible vegetation is planted in the floodplain of the waterway with a compound section,and that turbulence intensity peak is transferred to the floodplain from the intersection between the floodplain and the main channel.Turbulence intensity of flow in the floodplain decreases gradually along the river while that in the intersection region between the floodplain and the main channel increases.Turbulence intensity in the main channel is associated with the roughness of bed surface.Vegetations in the floodplain affect the time coming into the main channel of the floodplain flow and arouse the increase of flow velocity in the main channel along the river.