According to the characteristics of reinforced concrete nondestructive testing (NDT) and the detective principle of ultra wide band (UWB) radar, a handheld high resolution UWB ground penetrating radar (GPR) system was developed. The structure and principle of the low-cost RF module with the base-band pulse transmitter, the equivalent time sampling receiver and the UWB antenna were described. Design methods of the embedded control module, whose functions included radar control, data acquisition and the image processing, were introduced. The integration of hardware and software improved the portability, the stability and the real-time implementation of the system. The prototype experiment results have demonstrated that this system can detect the protective layer thickness and the positions of Φ6 reinforcing steel bars effectively with 0~35 cm depth and intervals of no less than 6cm, and can reflect other characteristics of reinforced concrete.