A mounting apparatus for fan includes a receiving bracket for receiving the fan, and two securing boards for sandwiching the fan therebetween. The receiving bracket includes a pair of opposite sidewalls. A top flange is perpendicularly bent from a top edge of each sidewall. A slot is defined in the top flange and corresponding sidewall. The securing boards are perpendicular to the pair of sidewalls and mounted therebetween. Two securing tabs protrude laterally from two sides of each securing board and are respectively received in the slots of the receiving bracket. The securing tabs are blocked by the top flanges to prevent the securing boards moving with the fan in directions parallel to the sidewalls.