The problem of robust control for a class of Lipschitz nonlinear systems with disturbances is studiedand the problem of observer-based robust control for nonlinear systems is discussed.Firstlya state observer is constructed for the nonlinear system satisfying Lipschitz condition.Secondlyin consideration of the disturbance term in the systemthe sufficient conditions for the existence of the observer-based controller in two cases are given in the form of Linear Matrix Inequalities (LMI) according to Lyapunov theorythe calculation methods of observer gain matrix and controller gain matrix are obtained and the robust control of the nonlinear system is realized.Finallya numerical example is given to verify the effectiveness of the proposed method.