Abstract: In the lower Signal to Noise (S/N) ratio Direct Sequence Spread Spectrum (DS/SS) signals, the estimated Pseudo-Noise (PN) sequence has a problem of phase indetermination in the method based on eignanalysis techniques. In this paper, we propose a simple and valid approach to blind synchronization of DS/SS signals. The problem above can be resolved by the blind synchronization algorithm. The theoretic analysis and experimental results show that the approach can work well on the lower S/N ratio input signals.