A heat dissipation device includes a plurality of first, second and third fins arranged side by side and a fan. The fins define a plurality of parallel channels therein respectively for air flowing therethrough. The fan and the channels of the first fins corporately define an enhanced airflow path which is isolated from the channels of the second and third fins so that the fan entirely impels an airflow generated by the fan to pass through the channels of the first fins. The first fins are located corresponding to a portion of a bottom surface of a base for contacting with a heat-generating electronic component.