Abstract: With the popularity of recording equipment, re-recording becomes a popular attack method to remove watermarks embedded in audio signals. In order to resist re-recording attacks, a new robust audio watermarking algorithm for source tracking is proposed. The definition of logarithmic mean of coefficient (LMC) was given, and the properties of the logarithm mean of coefficients were analyzed. A DCT-based middle frequency domain watermark embedding method was proposed. The synchronization information was generated after the frame number was binarized, and the frame number and the watermark were embedded in the carrier signal audio frame. The simulation results show that the proposed algorithm has good imperceptibility and robustness, and can effectively resist a certain degree of re-recording attacks.