An optical diagnostic system consisting of a Mach-Zehnder interferometer with an image processor was used to study the kinetic process of crystal growth. The crystallization process of lysozyme protein by vapor diffusion was investigated. The interference fringes around the growing lysozyme crystal were observed in real time. The effects of sedimentation and diffusion were analyzed. The experiment demonstrates that the fluid physics characteristic has an obvious influence on the solidification of the crystal growing face. According to the present experiment, a discussion on the protein crystal growth has been advanced.

Key words: interference measurement, crystal growth, diffusion, sedimentation