An experimental study on separation performance of sieve tray column in binary and ternary distillation is made under total reflux conditions with different tray specifications. Two different flow regimes are observed on the tray in different concentration regions for the ethanol-water, ethanol-benzene and ethanol-benzene-water systems. The liquid holdup in the foam regime is well correlated in terms of the weir height, free area and vapor phase Reynolds number. Although higher mass transfer rate is observed in the foam regime than that in the froth regime, the dimensionless volumetric vapor phase diffusion flux in the foam and froth regimes are well correlated in terms of the ratio of Froude to Weber number, free area and vapor phase Reynolds number.