Abstract: The output problem of linear systems is studied by making use of variable structure control in this paper. The output sliding mode compensator is proposed, the output sliding mode equation and its properties are considered. And then the synthesis of switching function and control are given by applying sliding mode state observer and sliding mode dynamic compensator. It is shown that the output sliding mode equation is insensitive to parameter variations and disturbances while the sliding mode oc

Key words: variable structure control, sliding mode, observer