In two-phase dispersion coupling interphase mass transfer process, the variation of interfacial tension is an important factor affecting the dispersion. In this study, we described a microfluidic method for the determination of the transient interfacial tension (TIFT). The method has the advantage of determining TIFT during the whole droplet formation process, rather than only at the rupture moment as reported in previous studies. The TIFTs of several systems were determined. In certain systems, it has been found that the droplet size decreased with the increase of the dispersed phase flow rate, which is obviously different from the constant interfacial tension system. It has also been found that TIFT was mainly affected by two-phase flow rates, solute type and concentration, and droplet size. A semiempirical equation was finally established to predict TIFT. It has the potential to be used in a variety of industrial equipment with dispersionmass transfer coupling process. (c) 2016 American Institute of Chemical Engineers