The composition and optical characte ri stics of a self-made,real-time and microscopic dual wavelength holographic in terferometer for visualizing the concentration profiles on gas-liquid interface were reported in this paper.The principle and methods of measurement were also presented in detail.Using this interferometer,the distinct real-time interferen ce fringes indicating the concentration profiles of the gas-liquid interface fo r the three-component system of methanol-ethanol-CO 2 were obtained.The i nterfacial turbulence was also clearly observed.