Abstract: An empirical formula for the turbulence intensity in subemerged river flows with plant is deduced,considering tur bulence intensity as a function of velocity and its gradient.The existence of the turbulence intensity maximum is validated mathematically according to this formula.According to the laboratory experiments,the magnitude and location of the turbulence intensity maximum is influenced by both the submerged canopy and the river flow.The foliage-spacing influences the magnitude of the maximum turbulence intensity by increasing the resistance of river flow.The swing of the frond foliage contributes to the initial disturber of turbulence,therefore the location of this maximum is controlled by the canopy/water-depth ratio.The cross-sectional averaged velocity influences the stability of water flow and the height of bend canopy,therefore modifying the magnitude and location of this maximum.