This research focuses on an adaptive control method for a pulling motion of a fibril. From the viewpoint of the biotechnology, analyses of a mechanical characteristic of a fibril are important. For the analyses, the pulling motion of the fibril is conducted by a piezoelectric actuator with a cantilever. The fibril is attached at the tip of the cantilever, and is pull by the piezoelectric actuator. By this pulling motion, it is possible to measure the mechatronic parameters of the fibril. During the pulling motion, the mechatronic parameters of fibril are changed due to the pulling force. Therefore, it is hard to conduct the pulling motion at the desired force command such as the constant force. From this view point, this paper proposes the adaptive control method based on the recursive least squares algorithm (RLS). These mechanical parameters are estimated in real-time by RLS. By using these estimated parameters, the position command to achieve the force command is calculated. In the simulation, the proposed method is implemented, and the pulling motion with the contact force is simulated. The validity of the proposed method is confirmed from the simulation results.