Abstract: This paper presents a turbulent jet vertically discharged into a flow fieldof regular waves in the intermediate between deep and shallow water usingthe particle image velocimetry (PIV) technique. Phase average method wasused to extract the turbulent velocity from the PIV measurements. Four waveswith different wave heights were applied in the experiments. The resultsfirstly showed that the turbulent characteristics of jets are significantlyaffected by the wave height. The convection term is more sensitive than theturbulent diffusion term for the wave height change. In addition, the ratioof the turbulent diffusion term to the convection term is about 1 / 8\sim 1/ 3 to show that the effect of the turbulent diffusion can't be ignored intime-averaged N-S equations.