Suboptimal H-infinity controller is said to internally stabilize the closed loop transfer matrix. However, the stability of controller is not assured in conventional H-infinity control theory. Unstable controller can damage the whole system when the sensor fails or actuator saturates. This note presents a stable n-dimensional H-infinity controller and its parameterization for the LTI system based on the sufficient condition for existence of stable H-infinity controller. The stability of H-infinity controller and closed-loop transfer matrix are guaranteed if the positive-semidefinite solutions for the suggested three Riccati equations exist.