The paper proposes guaranted cost design of robust output feedback controller for continuous linear parametric uncertain systems. Propsed algorithms is computationaly simple and tightly connected with the Lyapunov stability theory and the LQR optimal state feedback design. The proposed approach allows for prescribing the structure of the output feedback gain matrix (including the decentralized one)by the designer. New design method proposed in this paper exploit genetic algorithm to design robust controller with guaranted cost of polytopic linear continuous-time systems. Numerical example is given to ilustrate the performance of the proposed robust controller.