An operation system, a surgical system, a control device, a distortion generating body, a surgical instrument and the like for detecting a force acting on an end effector are provided.The surgical system includes an arm including one or more links, an end effector arranged at a tip end of the arm, a first distortion detecting unit that detects distortion generated in the end effector, a second distortion detecting unit that detects distortion generated in the link, and a processing unit that calculates a force acting on the end effector in a living body on the basis of detection results of the first distortion detecting unit and the second distortion detecting unit.