Abstract: Fourier transformation is an ideal analghtial tool to process stable. For the analysis of non-stable signals, base functions with well behaved time frequency charecteristics is required In comparison with the harmonic base functions of FFT, the wavelet function bases are suitable for non-stable signal analysis . In this paper, the harmonic wavelet is used to study local singular non-stable signal. The time-frequency position of singular non-stable signal is determined by means of the decomposition results.