Abstract: A series of flume experiments are conducted to study the influence of vegetation patches of different density on the turbulence intensity of a river channel, using wooden cylinders of the same size distributed uniformly in space to simulate non-submerged rigid vegetation. This paper focuses on analysis of eight sets of different vegetation densities, based on the three-dimensional instantaneous velocities measured using ADV. Comparison and analysis of the measurements reveals that turbulence structure varies greatly across the wake zone downstream of a vegetation patch. Near the downstream edge of the patch, transverse distribution of turbulent energy shows two forms as the density is increasing: one peak at low vegetation density and two peaks on the right and left sides of the patch at high density. Longitudinal distribution behind the patch takes a peak-trough-peak wavy shape, and an increase in vegetation density reduces the spacing of these two peaks that vary in different trends. Turbulence intensity near the downstream edge of the patch increases with vegetation density, and the longitudinal variation in vertical turbulence intensity profiles manifests a trend that the greater the density, the greater its amplitudes. A warping phenomenon in the patch wake can be observed, which is stable in shape when the density is large enough.