The effects of gas-agitation and packing on hydrodynamics and mass transfer were investigated through experiments with air-kerosene (benzoic acid)-water system and corrugated-packing of calendering plate with hole. The holdup of gas, holdup of dispersed liquid phase and mass transfer coefficient increase and the flooding velocity decrease with the increase in superficial gas velocity. Over-agitation of gas causes over-dispersion and emulsification of dispersed liquid phase, reduction of mass transfer performance and even flooding. The mass transfer performance of a packed column is far better than that of an unpacked column.