A packet transmission system includes a plurality of nodes connected by a packet transmission path. A current-use packet transmission path is used as the packet transmission path when a fault does not occur, and a spare packet transmission path is used as the packet transmission path when the fault has occurred. Each of the plurality of nodes includes: a transfer mode switching section configured to switch a transfer mode when transferring a received packet to a destination node to a 1:1 transfer mode or a 1+1 transfer mode, wherein the packet is transferred by the current-use packet transmission path in the 1:1 transfer mode, but the spare packet transmission path is not used, and the packet is transferred by the current-use packet transmission path and the spare packet transmission path in the 1+1 transfer mode; a path controller configured to instruct the transfer mode switching section to switch the transfer mode; a packet transferring section configured to transfer the received packet in the 1:1 transfer mode when the fault does not occur in the packet transmission network; and a reception path selecting section configured to select one of the packets received from the current-use packet transmission path and the spare packet transmission path in the 1+1 transfer mode.