Provided is a suction nozzle structure of a vacuum cleaner for enhancing a foreign particle suction efficiency. The suction nozzle structure includes: a suction tube in which a negative pressure is formed; a suction hole formed at a bottom of the suction nozzle structure such that air and foreign particles are sucked by the negative pressure of the suction tube; an agitator installed at an upper side of the suction hole; an air guide provided with an air suction passage communicating the suction hole with the suction tube, for guiding air flow; and a foreign particle rotation-preventing portion formed protruding from the air guide, for preventing a foreign particle from rotating.