Abstract: For uncertain nonlinear systems under the conditon of actuator failures,the problem of robust guaranteed cost controller design with L₂-gain disturbance attenuation performance constraints is studied.A more practical and general model for actuator failures is put forward,and the concept and properties of robust guaranteed cost control system with L₂-gain disturbance attenuation performance are also presented.Furthermore,based on Hamilton-Jacobi-Isaacs inequalities approach,a sufficient condition is given,under which the closed-loop system with actuator failures is asymptotically stable with given anti-disturbance performace and the cost function owns an upper bound.A simulation example shows the efficiency of the design method.