Abstract: A heat-dissipating fan having a dust-proof structure includes a stator and a rotor. The stator includes a shaft and a bearing disposed in a shaft hole of the shaft. The rotor includes an axle inserted in the bearing. The axle of the rotor has an inner end connected with an axle seat. The axle seat is located in the shaft hole of the shaft. A slight gap is defined between an outer wall of the axle seat and an inner wall of the shaft hole. The outer wall of the axle seat has a plurality of guiding grooves to block external air from entering the bearing. The guiding grooves are spiral grooves or V-shaped grooves. The guiding grooves are used to expel the air along with the rotation of the rotor, achieving a dust-proof protective structure in a non-contact type to block external dust or water vapor from entering the bearing to influence the running of the bearing. The present invention can enhance the service life of the heat-dissipating fan.