In this paper, we propose a method of autonomous take-off and landing of small unmanned helicopter in time of peace or emergency. On a concrete target, the algorithm which can perform take-off and landing safety in time of peace, is built on basis of velocity control of helicopter. On the other hand, the flight called autorotation landing as a landing means in emergencies, such as an engine trouble, is automated. Autorotation is a flight method of getting energy from air and obtaining a thrust by falling. And we verified the validity of the method by performing experiment.