Abstract：An ultrasonic test of 48 concrete specimens under different loading conditions was completed，and the variation of ultrasonic pulse velocity，amplitude of first wave and maximal amplitude with the stress in concrete were researched. Contemporary，the Fourier transform and wavelet transform were used to deal with the ultrasonic signals，and it is the correlation of major frequency，amplitude of major frequency，spectrum area and stress of concrete that were analyzed. On these bases，the correlation of acoustic parameters and stress of concrete was proposed. The research shows that major frequency isn¢t sensitive to stress；the change of ultrasonic velocity and amplitude are insignificant；and the correlation between weighted spectral area and stress is sensitive and stable.
