A medical manipulator system including: a manipulator with a flexible insertion portion, a movable part at a distal end of the insertion portion, a detachable drive unit at a proximal end of the insertion portion, and a pair of tension transmission members transmitting a driving force generated in the drive unit to move the movable part； an input unit inputting an operation command for the manipulator； and a control unit controlling the drive unit based on the input operation command, the drive unit having a displacement sensor detecting displacement direction and amount of the tension transmission members and a tension-difference sensor detecting a tension difference between the tension transmission members, the control unit has a storage unit storing characteristics of the tension transmission members and a setting unit setting a control parameter for controlling the drive unit based on the characteristics and the detected tension difference, displacement amount and direction.
