Abstract: Based on the characteristics that energy fluctuation occurs during resonant vibration transfer in elastic medium, a kind of method was developed to identify the state of rubbing between rotor and engine-frame by using the evidence of energy distribution and its movement.The rubbing was identified by processing vibration signals using fast Fourier transform(FFT), understanding color maps by point of energy, and also combining time-domain charts, frequency charts and waterfall maps.Through experiments, it's proved that the method is applicable and also provides actual evidence in engineering application.