Abstract: In this paper, a new method is explored for synthesizing range profile of a moving target via stepped frequency signal. The principle of synthesizing range profile of an extended target is investigated for stepped frequency signal. The distortion of synthetic range profiles is discussed with the theory of Discrete Fourier Transform (DFT). Based on phase cancellation, a new technology is proposed to achieve range profile with out distortion for a moving target. The new technology does not need the estimation of the velocity. The result of emulation proves the effect of the method.