Analysis of how motion characteristics of radar platform influence imaging is the premise of researching on motion compensation, detection, recognition and tracking methods. Aiming at the problem of radar platform motion characteristics and its effect on range profile, the study firstly analyzed the motion characteristics of radar platform, gave an LFM signal model based on motion platform, and quantitatively analyzed the influence on range profile which result from the motion characteristics of the radar platform. It is concluded that, under the condition of general radar platform, the micro-motion of platform influencing the radial velocity/acceleration can be ignored; the translational-motion of platform is the main factor influencing the range profile, the micro-motion of platform have little influence on range profile; radial acceleration influencing the range profile can be ignored. Finally, the simulation results verify the correctness of conclusion.