This paper presented a robust multiple faults diagnosis scheme for a class of nonlinear systems with actuator faults and sensor faults.First,the corresponding models were constructed for each possible form of actuator fault.A group of sliding mode observers were then designed,which produce residuals used to indicate different faults.With the use of a simple filter,the sensor faults were transformed into actuator faults,which make it possible that fault detection and isolation methods for actuator faults are applied on the situation where actuator faults and sensor faults occur simultaneously.A singlelink robotic arm simulation example was used to illustrate the effectiveness of the proposed methodology.