A disk drive/player positioning structure includes a bracket, a sliding bottom plate coupled and movable forwards/backwards relative to the bracket, two sliding side plates coupled between the sliding bottom plate and the bracket for longitudinal displacement with the sliding bottom plate and transversely movable to each other relative to the bracket, and a disk drive/player mounted on the sliding bottom plate. The disk drive/player is locked that the disk drive/player is pushed backwards with the sliding bottom plate relative to the bracket and the sliding side plates are moved inwards toward each other to force locating rods thereof into respective locating holes in the disk drive/player, and is unlocked that the disk drive/player is pushed forwards with the sliding bottom plate relative to the bracket and the sliding side plates are moved outwards to disengage the locating rods from the locating holes of the disk drive/player.