A heat dissipation device includes a first fin group, a second fin group, a heat pipe and a base. The base is in thermal contact with a heat source. The heat pipe includes a first pipe part and a second pipe part. The second pipe part is connected with the first pipe part and extended upwardly. The first pipe part is arranged between the base and the second fin group. The second pipe part is penetrated through the first fin group. The distance between a top surface of the first fin group and the base is larger than the distance between a top surface of the second fin group and the base. Since influences of the dissipating area and the wind resistance are taken into consideration, the heat dissipation device has enhanced heat dissipating efficacy.