Abstract: An audio watermark algorithm based on odd-even quantification is proposed which has the features as follows.（1）The synchronous signal area is a section of audio signal which bares a definite length and a large amount of energy.So it is retrieved efficiently to satisfy the condition in the time domain of the audio signal.（2）The watermark image is divided into several blocks and then the small blocks and their serial number are embedded into the wavelet transformation low-frequency coefficients circularly to ensure that the watermark can be exacted accurately from the other audio signal session when some audio signals are cut off.（3）The watermark algorithm is a blind watermark detection algorithm which has no use to reference the original audio signal. The experiments prove the imperceptibility of the watermark and the robustness to the familiar attacks especially to the synchronous attacks and dithering attacks.