Abstract: For the study of jamming effect of monopulse radar seeker by blinking jamming, regularity for change of two-plane formation line-of-sight angle is analyzed. The received signals of the seeker is analyzed and regularity for change of composite signal and relevant line-of-sight angle is analyzed. The analysis and simulation show that blinking jamming makes two-plane formation line-of-sight angle step transition, which is affected by the parameters of jamming resources, actual line-of-sight angle of actual objects and the power ratio of the jammers.