Mass transfer coefficients are one of the most important parameters for the design of liquid-liquid extraction columns. The mass transfer coefficients of single drops in a pilot structured packed column have been measured using toluene/acetic acid/water and n-butyl acetate/acetic acid/water systems. Current research shows that theoretical models have failed to predict mass transfer coefficient precisely and are not reliable for design. In this work an empirical correlation for prediction of enhancement factor is developed. Dispersed phase mass transfer coefficients predicted by the proposed correlation are in good compatibility with experimental results.