Provided are an apparatus and a method for controlling human body contact of ground electrode, and a human body communication system using the same. The apparatus includes a resistance measuring unit for applying a predetermined voltage to a human body through a signal electrode, to measure a resistance value between the signal electrode and the ground electrode; a contact control unit for determining whether the ground electrode needs to contact the human body by using the measured resistance value, to provide control information associated with human body contact; and a contact performing unit for bringing the ground electrode into contact or out of contact with the human body according to the control information.