Acoustic emission (AE) technique was used for the assessment of dental soldering Specimens were cast from removable partial denture alloy and then placed in a jig with a gap distance of 1.0 mm. A high-frequency soldering machine equipped with an optical pyrometer was used for the control of the soldering temperature at 1200℃. The flux was pure flux powder. During soldering, acoustic emissions in the frequency range of 10-400 KHz were collected, filtered, recorded, and processed by a piezoelectric sensing device. The acoustic emission signals were analyzed by analytical program written by Matlab Version 5.0.