This paper is a study on the minute grasping force control of a two-fingered miniature gripper driven by piezoelectric bimorph cells. The system is composed of two flexible fingers and a compact force sensor attached to the tip of one finger. Control action is implemented by two piezoelectric bimorph strips placed at the base of each finger. The theoretical model of the electromechanical system is developed and applied to the study of control problem where the gripper is commanded to grasp its object with a constant force 0.01 N at a prescribed fingertip position. The PID control algorithm is introduced to drive the gripper. The system control behaviour is examined both theoretically and experimentally.