Ultrasonic velocities and dimensions of sandstone specimens from Jiaozuo that experience different temperature(100 ℃－1 200 ℃) are measured; and their uniaxial strength are tested. P-wave attenuation coefficients of rock specimens are calculated. Crack densities are calculated using relations between ultrasonic velocity and elastic moduli. The volumes

ultrasonic velocities and attenuation coefficients of sandstone specimens before and after high temperature are compared. Results show that the cracks of sandstone specimens develop so that the compactness and ultrasonic velocities of specimens decline. For sandstone specimens that experience different temperature the changes of ultrasonic velocity and uniaxial strength are obviously discrepant. But changes of attenuation coefficients are similar to uniaxial strength. It can be taken as reference to evaluate uniaxial strength at a certain extent.