To provide a fuel discharge structure of a fuel line in which fuel piled up in the middle of the fuel line is suitably discharged when an engine stops, fuel can be prevented from leaking through an injector, and excess of fuel can be prevented from injecting into the engine when the engine restarts.

In a regulator, a housing is connected to a valve seat to form a chamber, a fuel inflow port is formed at one side of the chamber, an fuel outflow port is formed at the valve seat, a valve elastically supported with a spring is mounted at an upper side of the valve seat, and pressure of the fuel pumped up from a fuel pump into a fuel line is regulated. A separate bypass passage is connected between the middle of the fuel inflow port and the middle of the fuel outflow port of the regulator. The fuel remaining in the fuel line during the engine stoppage is formed to flow into a fuel tank side through the bypass passage.