In this study, we investigated a highly hydrated gel phantom with electrical anisotropy that can be used at 18.375 MHz to 23.625 MHz. This is one of the frequency bands used for human body communication. To achieve the communication, the electrical characteristics of the quadriceps femoris muscle of the rat were measured immediately after sacrifice. These were used to obtain an indicator of electrical characteristics to be satisfied by the phantom. Electrical anisotropy was realized by adding carbon fiber to the phantom and controlling its direction. We were able to develop a high hydrated gel phantom for human body communication with a maximum error of 8.1% assuming its use at 18.735 MHz to 23.625 MHz.