A novel switching function which replaces the sign function is presented in order to reduce high frequency chat-tering of the sliding model control. The dynamics model of multi-DOF serial robot manipulators is studied. A slid-ing control law with this novel switching function is designed and the asymptotic stability of the sliding model control of robot manipulators is proved. The simulation experiments of the sliding model control of 2-DOF robot manipulators illustrate that two links have higher angular position tracking accuracy and speed tracking accuracy. Moreover, its dynamic response is faster. The sliding model control system with the novel switching function re-duces high frequency chattering effectively compared with the sliding model control system with the sign function. This novel switching function can be used on other sliding model control systems, for instance, the airborne elec-tro-optical stabilized platform and missile guidance.