The present invention discloses a heating dissipating structure of an external hard disk drive box that includes a retaining base for mounting a hard disk, and the retaining base has adjusting rods that can be moved vertically up and down, and the retaining base and hard disk are covered by a heat dissipating cover, such that when the invention is assembled, the adjusting rods are rotated and pressed onto the heat dissipating cover, and the heat dissipating cover is attached closely onto the surface of the hard disk, and there exists no gap between the heat dissipating cover and the hard disk, so as to conduct the heat produced by the hard disk rapidly from the heat dissipating cover to the avoid and prevent any breakdown or failure due to an overheating.