Abstract: A new and improved horizontal posture maintenance structure which permits being restored to the original horizontal condition in defiance of inclination at rolling, pitching or swing place and maintaining the original state thereof by righting moment in accordance with gravity of the structure comprising two pairs of similar figure elements which are pivotally fitted at the each end and are rotatably supported at the bottom and also are spread at right angles to each other. A small type of the horizontal posture maintenance structure of the present invention is hung on a wall or is put on a table, and a large type of the structure is removably installed on a floor board. Excellent effect for restoration and maintenance of horizontal posture and condition, such as on rolling, pitching or swing place, is obtained.