Abstract: Friction damper is one of the most useful measures to alleviate the blade vibration stress and to prevent it from failure of fatigue.The procedures of design and optimization for platform friction damper of blades are proposed.Influences of friction coefficient and tangential stiffness of damper on the vibratory response are investigated.Steps which should be taken in design procedures in consideration of these two factors are proposed.One of the most important parameters should be optimized is the normal load after the material and geometry of friction contact are selected.Because of the difficulties encoutered in practice to accurately analyse the aerodynamic excitation and the viscous damping of blades,the effects of the excitation amplitude and viscous damping on the optimal value of normal load are studied based on both the calculation and experimental data.A procedure to optimize the normal load is introduced which is also insensitive to the value of excitation and viscous damping.