An apparatus (10) for performance testing of heat dissipating modules (19) includes an enclosure (11) configured for receiving the heat dissipating module therein, a vertically movable platform (13) for supporting the enclosure thereon, a boosting mechanism (18) configured for raising the vertically movable platform, and a force gage (12) having a force-sensing portion (121) configured for abutting against a top of the heat dissipating module. The enclosure includes a mounting base (110) having a plurality of mounting holes (1101) defined therein configured for mounting of heat dissipating modules with various sizes thereon. The present heat dissipating module testing apparatus can fit heat dissipating modules with various sizes. Thus saving both cost and time in testing.