With the fast developing portable digital audio player, the copyright protection of music faces a severe challenge. Audio watermarking is an efficient approach to solve this problem. In order to improve the performance of real-time processing, a new real-time audio watermarking based on fast MCLT is presented. Algorithms, which use of quantitative method, can be realized watermark blind detection. The experiment results show that the algorithm, which is utilized in the copyright protection, meet the timely processing requirements. Embedded of watermark audio have obviously robustness and transparency compared to the traditional methods. Furthermore, it can against MP3 compression attacks efficiently.