In order to evaluate the position and shape of the structural damage, a damage visualization technique using interference energy calculation method is presented. Based on the wavefield visualization technique, this study analyzes the effects on ultrasonic wave propagation caused by the damage. To extract the interference energy from the wavefield near the damage, Fourier transform in both time and space domains is used to separate the incident and reflected wavefields and then the inference energy is calculated to image the damage. Due to the interference energy caused by the damage spreads widely, Morlet wavelet transform is used in broadband signal processing to improve the resolution of the damage imaging. After narrowband signal extraction, interference energy calculation is followed and the signal to noise ratio of the damage imaging is improved.