The SELF-CLOSING RING BINDER relates to a binding mechanism comprising of opening bars, ring posts and base plate. The opening bars are attached to one leg of each ring posts and are designed to be connection parts to the other legs of the corresponding ring posts. In order to keep the opening bars closed between the legs of ring posts, the retaining force of metal springs and/or magnetism are employed. The retain springs are placed at the connection points between the opening bars and a leg of ring posts, and enable the openings bars closed automatically and anchored at the leg of corresponding ring posts. The magnetic may be pasted at both adjoining sides of the opening bars and the legs of ring posts, which help the opening bars contacted to the corresponding legs of ring posts. This binding mechanism is embodied on the cover.