Abstract: Inertial stabilization of line of sight (LOS) achieved by controlling the motion of a mirror in the optical path is used widely in various electro-optical reconnaissance systems on aircrafts, ships and ground vehicles. To improve the mirror stabilization performance, the system configurations and applications of the stabilized mirror systems are introduced. The optical path of the mirror and the system stabilization concept with half angle mechanism based on kinematics are described. The configurations and servo control techniques of several strap-down mirror systems are given. The key factors influencing the mirror stabilization are discussed for further engineering developments.