The key chain is a daily life article commonly used to hang the key. The music key chain of the invention can not only hang the key, but also play music, which can relieve the pressure of work for people. It is to install a music playing device in the heart-shaped ornament of an ordinary key chain. It includes a very small MP3 playing chip, a small headset, a key switch and a button battery, and then connect the MP3 playing chip, headset, key switch and button battery in series, which looks like an ordinary key chain. In leisure or need to relieve work pressure.