The paper addresses the robust adaptive control problem of robot manipulators. The dynamic equations of robot manipulators and their fundamental properties that facilitate analysis and control system design are first reviewed. Then the direct, indirect, and combined direct and indirect adaptive control approaches of robot manipulators are presented. After that, a number of variable structure adaptive control approaches which combines features of the robust design based on variable structure systems with parameter adaptive control, are studied. After that, a new combined adaptive and variable structure adaptive control approach is proposed for the tracking control of robot manipulators under the uncertainty environment. This is a robust, high-performance adaptive control scheme that combines the advantages and overcomes the disadvantages of both types of techniques. Finally, the extensive comparing simulation results are presented to demonstrate the theory study.