A cooling fan structure includes a driving device having a rotatable section disposed therein for providing a rotatable effect. The rotatable section has a first end longitudinally extending to a top of the driving device and a second end longitudinally extending to a bottom of the driving device. A set of fan blades is radially mounted to the rotatable section of the driving device and driven by the rotatable section. Each fan blade has an inner end. The inner end has a first connection and a second connection respectively extending therefrom. The first connection of each fan blade is connected to the first end of the rotatable section. The second connection of each fan blade is connected to the second end of the rotatable section.