Abstract: Abstract: The researches on high-resolution radar and the relative signal processing have great importance not only for multiple targets resolution but also for high-resolution imaging. Stepped-frequency radar technology is one of the common approaches to generating high range resolution profiles. In this paper, variable pulse repetition time(PRT) stepped-frequency waveform is introduced. Using this waveform, the quadratic phase term caused by the moving target can be eliminated. By transmitting two frames of variable PRT stepped-frequency waveform, a new method for measuring the range and velocity of the target simultaneously is proposed. According to the problem of measuring multiple velocities in the multiple targets scenario, a method based on variable PRT stepped-frequency waveform to measure the ranges and velocities of various targets simultaneously in the multiple targets scenario is proposed. Through the analysis of the relations of the targets in the high range resolution profiles generated by the two frames of variable PRT stepped-frequency waveform, the conditions for applying the new method have been determined. Therefore, by selecting the parameters of the stepped-frequency waveform properly, the ranges and velocities of all the targets can be measured simultaneously. The effectiveness of the method is illustrated with simulation results.