Abstract: The signal of a ground penetrating radar is a non stationary random one. In this paper, an introduction to wavelet transform and multi resolution analysis is presented. three common data compression methods based on wavelet transform for spectral information are descrbied. The data of a ground penetrating radar data compessed by the Daubechies compactly supported orthogonal wavelet and the orthogonal cubic B splines wavelet are compared. The results show that the orthogonal cubic B splines wavelet can get high effectiveness and can achieve a lange data compression ratio.