Abstract: A novel active cancellation method against synthetic aperture radar (SAR) is proposed theoretically based on the intermittent sampling. The cancellation signal is intermittent sampled to form the desired jamming signal. The jamming signal can both cancel the real target echo and form verisimilar false targets on SAR image simultaneously. First, the basic principles of SAR target active cancellation are introduced. Then, the active cancellation method based on intermittent sampling is theoretically derived. On this basis, the effects of the parameter error and key intermittent-sampling parameters on active cancellation and false-targets generation are studied. The key factors affecting the active cancellation and the distribution of two-dimensional false targets are also given. Simulation results verify the effectiveness of the proposed method.