Abstract: Five measuring methods of refractive index of liquid are introduced. It includes method of irradiation of laser, method of diffraction grating, method of optical fiber Young＇s interference, method of Abbemat refractometer, and method of measuring by CCD. All of these methods are simple for operation, and their principles are easy to understand. The characters of each method are also analysed.

Key words: liquid, refractive index, measuring method