Abstract: The current commonly used methods of detecting the strength of concrete are rebound method, ultrasonic-rebound combined method and core drilling method. In the case of the quality differences between the surface and internal of concrete, single rebound method can not reflect the actual situation of the internal strength of concrete. We can use core drilling method to amend the measurements. After amending by drilled core, this paper contrasts the differences of the measurements between rebound method and ultrasonic-rebound combined method. Then, we can select the more reasonable method.