Wind tunnel test on propeller for the 2 m class solar powered UAV is to consider aerodynamic efficiency of propeller before selecting optimum propulsion system. The propellers for wind tunnel test are Aeronaut folding propellers and APC propellers which have 14 to 18 inch diameter and 6 to 10 inch pitch in response to the previous examples of solar powered UAV design. Wind tunnel test is conducted by using the way of controlling RPM of electric motor in the constant wind tunnel speed which is the cruising speed of airship. In order to select optimum propeller in the flying requirements, thrust, torque and rpm are measured for several wind tunnel speeds (i.e., 5, 7, 10 m/s) at the same time. The required power for working with only propeller and propellers’ effic iency obtained by several wind tunnel tests are compared. Through wind tunnel test, suitable propellers can be in the flying requirements