Micro aerial vehicles (MAVs) have attained a great deal of attention in the past decade due to maturing technologies that have made them feasible and cost-effective. Although the majority of current vehicle concepts rely on fixed wing or rotorcraft [1], flapping wing flight provides superior maneuverability which would be necessary in obstacle avoidance and navigation in small spaces, as demonstrated by biological flying insects. By using flapping wings, the birds and insects effectively increase the Reynolds number without increasing their forward flight speed. Conceivably, the size of an aircraft could be reduced to a size of few millimeters as observed in nature. On the other hand, the propulsion of flapping wing has unique advantage over other type propulsion systems such as generation of lift force and thrust without excessive size or weight [2]. Hence the flapping wing is an efficient/useful option in designing smaller vehicles like the Micro Air Vehicles. It has taken almost one hundred years of development in flapping-wing flight. It seems to have been Knoller in 1909 and Betz in 1912 who first discovered that a flapping wing produces thrust [3]. At Present, there have a lot of investigation on aerodynamic force of flapping wing. At the Naval Postgraduate School, Jones and Platzer investigated propulsion and power-extraction using a two-dimensional unsteady panel method [4]. The problem of flapping wing propulsion has been considered by Liu using vortex lattice and panel methods [5]. The unsteady aerodynamic force effects(Lift and Thrust)on wing design parameters were discussed by A. Muniappan [6].Nevertheless, the investigation is very little on the effect of mechanism parameters on aerodynamic force. The prime objective of this work is to investigate the effect of mechanism parameters viz., the maximum angle of flap and flapping frequency on the development of the aerodynamic force by the wing flapping. These mechanism parameters are common for other types of flapping mechanism. Hence the results of experiment are directly applicable to other types of flapping mechanism. LIFT AND THRUST CHARACTERISTICS OF THE FLAPPING WING MICRO AIR VEHICLE Zhang Yafeng*, Li Zhanke*,Song Wenping,Song Bifeng School of Aeronautics, Northwestern Polytechnical University, Xi’an 710072, China