Abstract: According to the transfer processes of gas,a theory is analyzed for dissolved gas supersaturation downstream of the sluicing dam.The effective saturation concentration and the effective depth where bubbles are entrapped into water are introduced to explain consideration of the gas transfer across both the water surface and the bubble interface.It is difficult to measure many parameters such as the gas transfer coefficients,the bubble size,the air void ratio and so on.So the quantitative relations between these parameters and the water turbulence parameters,such as flow velocity,turbulence kinetic energy,are developed Taking the Ice Harbor dam in U.S.for example,the dissolved gas concentrations downstream of the dam are simulated using the theoretical relations.The local measured data show the validation of the theory.