A heat-dissipation unit coated with oxidation-resistant nano thin film includes a metal main body having a heat-absorbing portion and a heat-dissipating portion, both of which are coated with at least a nano metal compound thin film. To form the nano metal compound thin film on the heat-dissipation unit, first form at least a nano compound coating on an outer surface of the heat-dissipation unit, and then supply a reduction gas into a high-temperature environment to perform a heat treatment and a reduction process on the heat-dissipation unit and the nano compound coating thereof, and finally, a nano metal compound thin film is formed on the surface of the heat-dissipation unit after completion of the heat treatment and the reduction process. With the nano metal compound thin film, the heat-dissipation unit is protected against formation of oxide on its surface and accordingly against occurrence of increased thermal resistance thereof.