A fixing structure applied to arrange a heat dissipating device to a heat generating body on an object includes an entrance portion provided on the heat dissipating device and an elastic fastener provided on the object. The elastic fastener is arranged on the object, and includes a coupling head, a rod connected to the coupling head, and an elastic element sleeved on the rod. The entrance portion is in communication with a slide portion, and the elastic fastener is adapted to enter the slide portion by the rod via the entrance portion and have the coupling head contact the heat dissipating device. The elastic element is for providing an elastic force for tightly securing the coupling head on the heat dissipating device, so as to press the heat dissipating device against the heat generating body in order to dissipate heat.