Personal area network requires wireless communication system for exchanging information among wearable electronic devices. Intra-body communication that uses a human body as a transmission medium allows wireless communication without using airborne radio waves. Measurements of transmission characteristics of intra-body communication have shown that the optimum carrier frequency was 5MHz. Audio frequency signal was successfully transmitted through a human body using newly developed 10.7MHz FM transmitter and receiver modules, both having the size of 3cm by 3cm. The carrier frequency was selected to utilize commercial RF devices.