Provided is a power line communication system in which power line communication devices having different configurations from each other coexist. A charging station performs power line communication, using a signal superimposition/separation section in which a capacitor, a coupling transformer, and a capacitor are connected to branch lines branched from two AC lines. An electric vehicle performs power line communication, using a signal superimposition/separation section in which the coupling transformer is inserted in one AC line and a capacitor is connected to and between two AC lines. In a case where the charging station and the electric vehicle are connected to each other with a charging cable, a closed loop circuit is formed that is composed of the AC line, the branch line, the capacitor, a primary coil of the coupling transformer, the capacitor, the branch line, the AC line, an AC line, the AC line, the capacitor, a primary coil of a coupling transformer, the AC line, and an AC line. Thus, power line communication can be performed.