A new radial velocity estimation method was presented to compensate the effects of the target-s radial velocity on range profiles synthesized from a stepped-frequency radar. Theoretical analysis indicates that the correlation function derived from two sequential bursts- normalized complex samples of a stepped-frequency radar is a complex sinusoidal sequence, and the sequence-s frequency is related to the target-s radial velocity. So the target-s radial velocity can be estimated with the sequence-s frequency calculated by fast Fourier transform(FFT) algorithm. The estimable velocity range of this method is applicable depends only on the system bandwidth and the pulse repetition period. As the theoretical estimation resolution is determined by the point number of FFT, computational cost can be saved in the case of high estimation resolution is required.Simulation results show that this method can estimate the target’s radial velocity accurately with good anti-noise performance.