A. C. impedance measurements were applied to study a stability of W/O emulsion. Measurement frequency range was from 10mHz to 100kHz. Diameter of aqueous phase changed smaller with increasing of agitating power at emulsification. Emulsion was observed by Cryo-SEM. The impedance at low frequency showed the whole resistance of emulsion. It was about equal to oil phase resistance when water phases were surrounded with oil phase respectively. Coalescence of emulsion has grown at 60°C faster than room temperature. It's change can be detected by decreasing of impedance at low frequency and obsurved by Cryo-SEM.
