In this paper, the concept of CWP(combined wavelet packets) is proposed. CWP can be obtained from COWB(combined orthonormal wavelet bases) which is composed of several orthonormal wavelet bases having the same space structure in a multiresolution analysis view. Compared with traditional wavelet packets, CWP have not only better frequency localization, but also waveshape variation. The wavelet coefficients can be computed by a fast algorithm which computes in the frequency domain and uses FFT.