Abstract: A structure of heat dissipating fins that can be assembled with increased efficiency without the use of adhesive agents such as soldering tin, and so on, while ensuring a tight fit on cooling ducts. More than one through hole defined in each of the heat dissipating fins that provide for cooling ducts to insert therein. A staircase-like member extends backward from each of the through holes to form a catch groove, and a catch end further extends backward from each of the catch grooves. When the heat dissipating fins are being successively disposed onto the cooling ducts through the through holes, the catch ends are respectively disposed into the catch grooves of the heat dissipating fin positioned therebehind, thereby producing a tight clamping effect on the cooling ducts, further causing an immobile mutual fastening between the heat dissipating fins without the use of soldering tin.