A new manufacturing method of the cup type composite flexspline for a harmonic drive is developed using adhesive joining technology to obviate the manufacturing difficulty of the conventional one-piece cup type steel flexspline. and to improve the dynamic characteristics of the flexspline.In this method, the boss, tube, and tooth sections of the flexspline are designed and manufactured separately, and adhesively bonded. The tube section is manufactured with high strength carbon fiber epoxy composite materials and its dynamic properties are compared with the conventional steel flexspline.From the test results of the manufactured composite flexspline and the conventional steel flexspline, it was found that the manufactured composite flexspline had better torque transmission capability, and the stiffness in the circumferential direction. Also. it was found that the damping of the composite flexspline were considerably improved.