Abstract: A virtual force guided control method for network-based tele-robotic systems is presented to obtain force effect before the slave robot contacts with the object to be grasped.Relative posture between the end-effector and the object to be grasped is obtained based on the monocular vision technology,and it is transformed into force feedback information to which operators are more sensitive.The operator can give proper commands to control the slave robot to achieve the desired final posture under the guidance of the virtual force information.A demonstration setup is developed with man-made targets and the camera fixed on the wrist of the robot.Teleoperation experiments are conducted under robot position control mode and attitude control mode respectively,which demonstrate the improvement of operability and efficiency of the tele-robotic system.