The objective of acoustic emission measurement at Japan Atomic Energy Research Institute is an establishment of a general diagnostic method for superconducting magnet systems. Monitoring of acoustic emission will be one of the methods to predict a serious failure of magnet systems in a vacuum vessel. For this purpose, several sensors were installed on the Japanese LCT coil and the Test Module coil (TMC). Some of acoustic activity was similar as seen in these coils. The correlation between voltage spikes and acoustic events is excellent during single coil charging mode, but poorer during out of plane force mode. The acoustic emission of the Poloidal Unit Pancake (PUP) was monitored in the first case of the pulse poloidal coil for fusion. The localization of electrical insulation damage with the acoustic emission technique is one of its most useful applications.