Stage support platform is composed of a leg connector(l) between legs(5) which is in shape of a stick or tube amounted two unit combining together in the way that it could be expanding out or foldable in. Each ends of the stick or tube is inserted into a side groove(3) of combining a base(4) in the way that it could sway forward-backward. Between the vertical combining base(4), it is combined by an insertion support tube(8) of which its part is an inside moving in-out axle(9) that is able to move in-out from the inside of insertion support tube for holding in-out by the folding in-out of the leg connector(l) between the legs(5). The side groove(3) of the combining base(4) which is in vertical side of a main stage support contains connecting part that is expandable in-out attached at its side for extending in-out additional from the main stage support.
