Abstract: The design of an output feedback controller is investigated to enable a closed-loop system to be asymptotically stable for a class of uncertain systems. A controller is proposed including both nonlinear and linear parts, and the latter is stressed in design. Dynamics is introduced completely to eliminate mismatched uncertainties and, on the other hand, the nonlinear part is simplified as possible. Based on the Lyapunov theory and LMI (linear matrix inequality), the sufficient conditions for the existence of the control law of dynamic output feedback variable structure are derived and transformed into a feasibility problem in terms of LMI. The problem can thus be solved by Matlab LMI toolbox so as to build the variable structure controller for a class of uncertain linear systems. A Matlab simulation example is given to illustrate that this analysis method and its results are valid and feasible.