A heat sink structure comprises: a heat conducting base being provided thereon with a plurality of heat sinking fins arranged longitudinally and transversely to mutually cross each other; with the help of the blowing air blown by an above installed fan, the heat sink can make a fast exchange of the cool air and hot air in the interspace among the heat sinking fins to help dissipate the heat generated by a CPU to the ambient to achieve the fast heat sinking effect. The structure is applied to a heat sink for a computer, an electronic instrument or some other heat generating electric component.