A heat dissipation device includes a heat conducting member (10) adapted for contacting with a heat generating electronic device and a fin unit (30). The fin unit defines a central hole (300) therein and consists of a plurality of fins (31) around the central hole and clasping each other. The fin unit fits around a periphery of the heat conducting member via the heat conducting member extending in the central hole of the fin unit. A clip (40) engages with the heat conducting member and the fin unit for providing a pressure to the fin unit such that the fin unit is intimately fastened to the heat conducting member.