A communication system for a vehicle that has a communication line (12, 13, 21) configured in a loop form having a joint connector (14, 15, 16, 17) provided at each of a plurality of connection positions on the communication line (12, 13, 21) providing a communication transmission path corresponding to the CAN communication standard, the communication system comprising: a disconnection detection part; a central gateway; and a communication path control part (27; 11), wherein the disconnection detection part detects presence or absence of disconnection in one or more communication lines (12, 13, 21); the communication system characterized by comprising: a path switch; wherein the path switch that is controllable to cut off a part of the communication line (12, 13, 21) in a steady state is provided inside or near one or a plurality of the joint connectors (14, 15, 16, 17); and in that the disconnection detection part is provided inside or near one or a plurality of the joint connectors (14, 15, 16, 17); the central gateway that has a routing map for controlling a communication path is connected to the communication line (12, 13, 21); and when the disconnection detection part detects presence of disconnection, the communication path control part (27; 11) switches one or a plurality of the path switches to a connected state, and changes content of the routing map to enable use of a path passing through the path switch. a disconnection detection part; a central gateway; and a communication path control part (27; 11), wherein the disconnection detection part detects presence or absence of disconnection in one or more communication lines (12, 13, 21); the communication system characterized by comprising: a path switch; wherein the path switch that is controllable to cut off a part of the communication line (12, 13, 21) in a steady state is provided inside or near one or a plurality of the joint connectors (14, 15, 16, 17); and in that the disconnection detection part is provided inside or near one or a plurality of the joint connectors (14, 15, 16, 17); the central gateway that has a routing map for controlling a communication path is connected to the communication line (12, 13, 21); and when the disconnection detection part detects presence of disconnection, the communication path control part (27; 11) switches one or a plurality of the path switches to a connected state, and changes content of the routing map to enable use of a path passing through the path switch. a path switch; wherein the path switch that is controllable to cut off a part of the communication line (12, 13, 21) in a steady state is provided inside or near one or a plurality of the joint connectors (14, 15, 16, 17); and in that the disconnection detection part is provided inside or near one or a plurality of the joint connectors (14, 15, 16, 17); the central gateway that has a routing map for controlling a communication path is connected to the communication line (12, 13, 21); and when the disconnection detection part detects presence of disconnection, the communication path control part (27; 11) switches one or a plurality of the path switches to a connected state, and changes content of the routing map to enable use of a path passing through the path switch.