Abstarct: GPR, Ground Penetrating Radar is one of the geophysical methods for natural and artificial subsurface investigations. In this method a transmitter antenna send a electromagnetic pulse to the ground and structures. These pulses are reflected by electrical inhemogenities and then received by a receiver antenna. One of the effective applications of this method is quality control of pavements. Primary aim of using this method in pavements is determination of thickness of laxyers. Also it is possible determining quality properties of pavements by this method. In a part of this study, GPR method is used for determining thickness of laxyers pavement in campus of Shahrood University of Technology. Determination of thickness laxyers of pavement was not successful, because center frequency of system was low. In the other part of this study, GPR method is used for determining of asphalt and baxse quality properties. For this purpose, asphalt and baxse samples are produced and then void content of asphalt and moisture of baxse is determined by GPR. In this method, dielectric constants of asphalt and baxse samples is determined by surface reflection method. Then, dielectric constants are related to void content of asphalt and moisture of baxse. Because cross section of asphalt and baxse samples are smaller than footprint of GPR, dielectric constant of these samples is bigger than their real values. However, there is a logical relationship between dielectric constant and quality properties of pavement.