Current investigation is focused on experimental analysis for the improvement of aerodynamic performances of low aspect ratio wings (S5010 profile, AR = 1,2) at low Reynolds number. In this study self-adjustable flap is used as a lift enhancement device, is mounted on the suction surface of the wing. Present mounting allows the flap to rotate freely about its leading-edge without supplying any external energy. All the experiment performed in open circuit subsonic wind tunnel for the chord-based Reynolds number is 105. It has been observed, the flap remains attached to the wing surface at low angles of attack. But, as the angle of attack increases, flow separation initiates to occur along the trailing edge which lift ups the flap and adjusts itself in a situation so that the flow reattaches. Hence, the lift curve, for pre-stall angles is almost identical in both clean and flapped configurations. Further, both the flap locations are seen to improve the lift coefficient than the clean airfoil for post-stall angles. The flap is more effective for both the models when it is located at a position of 70% of chord length.