Abstract: In a previous investigation in 1963 Wang and Shen et al,found that the well known flow equationfor pulsed sieve plate column given by J.D.Thornton should be modified and written asV_s=V_d/X+V_c/(1-x)=V_0(1-x)~nThis paper is a continuation of the previous works.Four kinds of liquid-liquid system were examinedin this study.The parameters n and V_o,the Sauter mean diameter of dispersed droplets D_(3.2) arc corro-leted in terms of physical properties of the systems and operation variables.Calculated flooding veloci-ties are close to the experimental values with deviation within ±15%.