An a Radio Frequency Identification (RFID) system using human body communication includes a first electrode pad receiving a signal of a reader transmitted through a human body, or outputting an output signal to the human body, a rectifier rectifying the signal of the reader to generate a direct current (DC) voltage, a power manager changing the DC voltage into an operation voltage, a modulator/demodulator demodulating the signal of the reader, or modulating the output signal of the tag to transfer the modulated signal to the first electrode pad, a digital controller performing a read or write operation in response to the signal of the reader demodulated by the modulator/demodulator, and a memory storing identification information of the tag and information according to an operation result of the digital controller.