Abstract: A three degree-of-freedom (3-DOF) Wind Tunnel Based Virtual Flight Test (WTBVFT) system is developed to study unstable aerodynamic phenomena and maneuver characteristics coupling with motion of high-performance fighters maneuvering at high angle of attack. Based on this system, a series of 3-DOF virtual flight tests of F-16 fighter are performed. As the results, the short-time modes of flight dynamics are simulated from wind tunnel tests with small angle of attack, and control law are validated in those tests. Then an instability phenomenon in pitch is detected from tests with high angle of attack. A group of lateral-directional unstable aerodynamic-coupling motions are detected from tests when angle of attack is less than zero. In these tests, augmentation control of aileron cannot recover lateral-directional stability of flight, but always leading to control coupling motion. It is more effective to adopt elevator control to change angle of attack to recover the lateral-directional stability.