Abstract: Through motion compensation of Inverse Synthetic Aperture Radar(ISAR), the jamming mechanism of ISAR is analyzed and simulated. The results show the imaging of ISAR will be distorted effectively if the maximum value of the complex envelope correlation function of neighbor range images is false alarm. Furthermore, the comparison of anti-jamming ability among ISAR, SAR and linear frequency-modulated radar shows that the anti-jamming ability of ISAR is worse because it needs motion compensation before imaging.