A fixing mechanism fixes a side of a fan frame having a plurality of cooling fans and two first connecting tabs opposing to each other to a bottom board of a housing. The fixing mechanism includes a first end portion fixed to the bottom board; a second end portion perpendicularly installed on the first end portion; two second connecting tabs corresponding to the first connecting tabs and installed on the second end portion; an elastic buffer installed between one of the first connecting tabs and one of the second connecting tabs corresponding to the one of the first connecting tabs; and an elastic arced strip passing through the first connecting tabs and the second connecting tabs, for holding the elastic buffer between the one of the first connecting tabs and the one of the second connecting tabs, so as to fixing the fixing mechanism to the fan frame.