Autonomous flight system using marker recognition on drone The DHL began test and research on delivery system by drone. Because of growing demand about comercialized and personal-use drone business, we needed a real-time unmanned drone control system that individuals can afford. In this paper, we propose an autonomous flight system for drone. We used marker recognition technique on that system because it doesn’t require high-spec device which cannot be afforded by ordinary people. The proposed system maintains distance between drone and marker in flight. The system estimates the distance between marker and drone by calculating area of recognized marker image. Performance is validated by result of the proposed system experiment with Parrot’s aerial vehicle AR.drone 2.0 and Android device. The proposed system is expected to be used in promising areas like chase camera, unmanned transport and etc.