A peer-to-peer connection system for peer-to-peer connection path routing provides an optimal connection path between a client electronic device and a target subsystem. The peer-to-peer connection system comprises a target subsystem, at least one relay subsystem and the client electronic device. The target subsystem and the relay subsystem connect to internet via different routers respectively. The target subsystem comprises a target device; the relay subsystem comprises a relay device. The target device and the relay device transmit a connection quality table to the client electronic device respectively. The client electronic device determines the optimal connection path according to the connection quality tables. This application program can provide the optimal peer-to-peer connection path via making the relay device be a relay node of peer-to-peer connection according to the connection quality tables.