The wing flexibility effect on the lift and drag has been investigated for various unswept composite wings through the low speed wind tunnel test. The models which were used in this test are six composite wings and a rigid wing. Composite wing models are made of graphite/epoxy prepreg and their layups are [O2/9O3]s, [302/9O3]s, [602/9O3]s, [9O-5]s/, [l202/9O3]s, and [1502/ 9O3]s. In the experimental test. lift and drag of composite wings are measured for various velocities and layups. The test data indicate that the variations of lift and drag are greatly affected` by the composite layups and the effects of composite layups on the drag which are difficult to predict from analytical methods have been investigated from wind tunnel test.