Abstract: Time reversal mirror (TRM) technique is based on the principle of reciprocity. This technique perfectly caters to the demands of detection range and resolution in the complex environment. Therefore, it attracts more and more attention recently. This paper combines the TRM technique with SAR (synthetic aperture radar) imaging technique, and introduces it to the ultra-wideband ground penetrating radar (UWB-GPR) system through numerical simulation and theoretical analysis. For real applications, we consider the detection environment of rough surface and random electrical parameter. The corresponding TRM-SAR images are compared with these of back projection (BP) method. Results show that TRM technique can provides the UWB-GPR system with higher resolution image.