Mass transfer in gas-liquid bubbling processas is commonly encountered in chemical engineering practice. Forthe research on interphase ma transfer. It is very importantto begin with the description of the interface it self, in which the concentration near the interface has to be pri-marily measured. Formerly, most models developed for describing interphase interphase mass transfer were pragmatically simplified in both of the interface an hydrodynamics. An apparent difficulty is to measure the concentration distribution in the intefacial region. This subject lay dormant until the development of holographic interference technique in early seventies and the experim ental study initiated by VII and his students in nineties [1, 2]. In this paper, two holographic intefer-ometers are successfully used to study the concentration field near the gas-liquid interface of a riaing bubble. The present study may be helpful to broaden the knowledge about the mechanism of mass transfer in bubbling process.