A fuel filler structure of a fuel feeding pipe prevents efficiency of sucking volatile fuel from being decreased during refueling even if a drain hole is formed, and includes: a cylinder (12) that includes an opening (18) and a connecting port (20); a first flap mechanism (26) that is arranged near the opening (18) of the cylinder (12) and opens the opening (18) when a nozzle is inserted; a drain hole (24) that is formed in the cylinder (12) and communicates inside the cylinder (12) with outside; and a drain hole switching valve (64) that opens and closes the drain hole (24), wherein the drain hole switching valve (64) has a closing mechanism (34) including a valve core part (38) closing the drain hole (24) (50) that is pressed by the nozzle when the nozzle is inserted through the opening (18), so that the drain hole (24) when a first open-close component (28) of the first flap mechanism (26) is closed.