Abstract:The longitudinal wave velocities are measured for 25 granite samples before and after high temperature. With the ultrasonic and conventional compression methods,the Young¢s moduli of granite after high temperature are determined. The longitudinal wave velocities and Young¢s moduli after high temperature are analyzed. The results show that the velocities of longitudinal wave decrease with temperature. The Young¢s modulus gained by ultrasonic method decreases more than that gained by conventional method. This means that the change of physical characteristics of granite is much severer than that of its mechanical characteristics after high temperature.