Abstract: When a pair of conventional compression wave ultrasonic transducers are placed on the surface of concrete, surface waves will be generated and propagate along the surface of the concrete. Due to the marked difference between the amplitude of compression waves and surface waves, the leading edge of surface waves can be identified on the waveform from a train of compression waves and can be measured. According to the relationship between the parameters of elasticity and the velocity of surface and compression waves, the dynamic modulus of elasticity and Poisson's ratio of concrete can be calculated.