Abstract: The existing methods adopted to monitor the fastener joint failure based on electromechanical impedance method demand for high quality equipment. At the same time, there was a lack of a unified method on the judge of fastener joint failure. Formulas were derived and a monitoring system was designed to investigate the feasibility of a new method based on the frequency spectrum of the real part of electrical admittance. The ample evidence presented enables us reasonably to conclude that fastener joint failure can be well monitored using frequency spectrum of real part of electrical admittance in the way mentioned.