Abstract: A carburetor and a fuel seeding system having the same including an air suction passageway through which air is fed, and a fuel feeding passageway which is disposed so as to be intersected to the air suction passageway and through which fuel is fed, the air suction passageway and the fuel feeding passageway being intercommunicated to each other. A roughened surface portion is formed on a wall surface of at least one of the air suction passageway and the fuel feeding passageway to generate turbulence in fluid flow and promote carburetion and granulation of the air-fuel mixture due to the turbulence. The tip portion of a jet needle serving as a part of the fuel feeding passageway may be provided with a substantially flat surface portion or a substantially conical surface portion having a vertical angle above 145 degrees.