Abstract: In this paper, by using the biorthogonal quadrature niters, the biorthogonal mul-tiresolution of finite dimension space equipped with inner product and the fast discrete wavelet transform (FDWT) are constructed. The dual transform method is proposed and the radar data storage is reduced by it. The method of choosing the wavelet coefficients, and the methods of correlation and nearest neighbor classification in wavelet domain based on the compressed data, are presented. The experimental results of the classification, using the high resolution range returns from six kinds of aircraft, show that the methods of transform, compression and recognition are efficient.