Abstract: The experimental research on the mechanical prope rties of granite rock and concrete after different high temperatures was conducted. The mechanical pr operties include stress-strain curve, peak stress, peak strain and Young’s mod ul us of granite rock and concrete. The results showed that the temperature did not obviously affect the mechanical properties of granite rock in the range from ro om temperature to 400℃. The mechanical properties of granite rock deteriorated rapidly with the increase of temperature when the temperature was above 400℃. The peak stress ( or the strength) and Young’s modulus decreased rapidly, while the peak strain in creased rapidly. However, the high temperature obviously affected the mechanical properties of concrete. With the increase of temperature,the peak stre ss (or the strength) and Young’s modulus of concrete decreased rapidly.