With the development of the Internet and mobile terminals, more and more pirate digital music resources are easily disseminated online.To prevent the illegal copies propagating among mobile devices and protect the right of content providers, this paper designs a Client/Server model based Digital Music Copyright Protection System (hence DMCPS) for mobile terminals.The system contains three parts: security channel, server and client.Security channel is established by defining a new protocol and identity authentication procedure between the server and the client.In the server, RC4algorithm is used to encrypt frame header and chaotic based digital watermark algorithm is used to embed the MD5 of the clients unique IMEI (International Mobile Equipment Identity) in each frame data.In the client, frame header is decrypted, and the embedded information is extracted and compared with its IMEI to decide whether to decode.The experimental results show that the system not only can effectively protect copyright for digital music, but also is of high efficiency for real-time application.Furthermore, our system is of high security with large key space, and the ability to resist brute force attack, noise attack and DDOS attack.