In this experiment, the inert gas is used to agitate two immiscible fluids in microchannels. The mass transfer performances with or without gas agitation are investigated. 30% TBP (in kerosene)-acetic acid-water is chosen as testing system. and nitrogen as agitating gas. The superficial velocities of the immiscible liquid-liquid two phases and gas phase are varied in the range from 0.02 to 1.2 m/s, and 0 to 3.0 m/s. respectively. In microchannels, with enough gas agitating intensity. high dispersion between two immiscible liquid phases can be obtained. The overall volumetric mean mass transfer coefficients are two-folds higher than those without gas agitating, which are in the range of 3.8-30.6 s(-1). Some parameters which impact on the mass transfer process, such as the mixture superficial velocity of the immiscible liquid-liquid two phases, the gas superficial velocity, the microchannel structure, the gas inlet locations and the sampling time are experimentally investigated. (C) 2009 American Institute of Chemical Engineers AIChE J, 55: 1948-1958, 2009