A magnetron sputtering cathode mechanism includes a backing plate, a target, at least one magnetic component and at least one magnet. The backing plate has a first surface and a second surface opposite to the first surface. The first surface has at least one positioning recess, and the target has a bombarded surface and a non-bombarded surface opposite to the bombarded surface. The non-bombarded surface contacts with the first surface and has at least one combining recess. The magnetic component is disposed between the backing plate and the target and has a combining portion and a positioning portion. The combining portion is positioned in the combining recess, and the positioning portion is received in the positioning recess. The magnet is disposed at the second surface. The magnetic component is attracted to the corresponding magnet so as to fix the target at the backing plate.