Abstract: As blinking jamming has been proven to be an effective countermeasure against monopulse seeker. It is necessary to study the mechanism of the effect of blinking jamming on monopulse seeker. Based on the angle tracking circuit model, influence of blinking jamming upon the angle measure and angle velocity measure of monopulse seeker is studied. Bandwidth of blinking jamming and each part of angle tracking system is analyzed, and the effect of blinking jamming on an angle tracking circuit is studied. The effect of different blinking frequency on the angle tracking system is simulated and evaluated to provide a guideline for the selection of blinking frequency.