A structure of a fuel door is provided. The fuel door includes a sector-shaped gear that uses a rotating shaft in conjunction with a hinge of fuel door, a first spring having a first end coupled to a housing and a second end coupled to the gear. The first spring applies an elastic force and rotates the gear in a direction that opens the fuel door. A latch is rotatably coupled to the housing by a hinge component having one end of the latch parallel to the rotating shaft of the gear. The latch has a first surface in contact with an exterior circumferential surface of the gear to restrict rotation of the gear and a second spring having a first end coupled to the housing, and a second end in contact with a second surface of the latch, the second spring translates the latch toward the gear.