Disclosed is a driving device for an automatic tracking operation of a solar panel for a solar power generator. The device includes a housing, a worm gear, and upper and lower ring bearings. The worm gear is coupled to a worm mounted to a worm shaft, and a rotary gear is connected to an end of the worm shaft to engage with a drive gear. A thrust bearing is mounted on an upper portion of the upper ring bearing, and an anchor plate and an upper casing are installed above the thrust bearing. A support plate and a lower casing are coupled to a lower portion of the lower ring bearing. First and second stoppers are securely provided on a bearing body of the lower ring bearing to touch first and second limit switches. The solar panel is supported on the housing via a panel support bracket.