Reactive extraction of lactic acid was performed continuously in a packed column. The 0.6 M trioctylamine (TOA)/1-chlorobutane system was used as an extractant. The initial concentration of lactic acid was 10 wt% based on fermentation results. Raschig rings (5 and 7 mm diameter) were used to measure hydrodynamic data. Disperse phase holdup was nearly constant at V-d<0.8V(d,f). It can be seen that the flooding data obtained from this study were consistent with the literature, NTU and HTU were calculated. NTU varied from 1 to 2 and HTU from 96 cm to 44 cm with variation of V-d. The overall mass transfer coefficients of the continuous phase were nearly constant to 8.98 x 10(-5) mol/cm(2)s will variation of V-d.