Radar image processing is a radar signals process with huge computation quantity, because it requires wider bandwidth and more pulse accumulation, and it becomes a big challenge to achieve real- time image process for ultra wide band in the future. Graphics Processing Unit(GPU) is the candidate for its excellent computing capability and memory access performance. A real-time Synthetic Aperture Radar/Inverse Synthetic Aperture Radar(SAR/ISAR) imaging system based on CPU+GPU hybrid architecture is designed and implemented. The results show that the real-time SAR/ISAR system can achieve wide band SAR/ISAR image process, and it can be applied in the electronic warfare field and play a key part in the jammer study and experiment.