This paper deals with the kinematic analysis of a shedding device. The shedding device is used for the weaving system of high-speed rapier looms. The device consists of two parts: a cam driving part and a link moving part. The cam driving part has a double cam system, of which two cams move in conjugate motion. The link moving part has a 4-bar linkage and a slider mechanism. For the shpe design of a positive conjugate double cam, an instant velocity center method is proposed. This method can determine the cam profile from the contact conditions of the cam and the roller follower and the velocity relationships at the instant velocity center velocity center. Also the closed-loop method is used to analyze the kinematic properties of slide motion in the link moving part. As the results in this paper, the shapes of two cams, which are in the conjugate motion, are designed by the instant velocity center method. The cycloid curve is used for the follower motion in the cam driving part. The kinematic characteristics of the slider in the link moving part are analyzed. The data of displacement, velocity, and acceleration of the slider can be used to adjust in the accurate operation and to develope an advanced shedding device.