An expansion card mounting apparatus including an enclosure, the enclosure including a support plate and a flange, the enclosure defining a slot, the support plate and the flange located above the slot; a mounting plate, the mounting plate including a mounting plate body and a bent portion extending from the mounting plate body; the mounting plate body securing an expansion card and covering the slot; the bent portion located on the support plate; a securing element, the securing element pressing the bent portion; and a pressing member, the pressing member including a resilient arm and a securing portion extending from the resilient arm; the resilient arm including a first and a second ends, the first end resisting the expansion card; the second end resisting on the securing element; and the securing portion engaging with the flange to enable the pressing member sandwiched between the securing element and the flange.