Abstract: How to use the wavelet packet theory to design radar waveform is studied in this paper. Based on the basic theory of wavelet and wavelet packet, the design method of cascading the wavelet packets to construct the radar waveform is proposed,through analyzing the characteristics of the wavelet packet. Three kinds of analysis tools, including the autocorrelation function, the ambiguity function and time鄄frequency distribution, are used to complete the performance analysis of the proposed radar waveform. The theoretical analysis and computer simulation results verify that the proposed radar waveform based on the wavelet packets shows significant advantages over conventional linear frequency modulated (LFM) for effective range resolution and intra pulse modulation characteristics. The research results of this paper can provide a new and practical idea for the design of radar waveform.