In this paper, the finite element modeling of Golf Club, prediction of radiation sound from the club, and structural modification to reduce the radiation sound are discussed. The golf club consists of head and shaft, and the club's characteristic (in particular damping ratio) is different from head, shaft each. In this paper, modeling of connection effect based on a structural damping is proposed. And volume acceleration is applied to predict the radiation sound from club head. Comparing volume acceleration and experimental radiation sound, it is shown that the relative frequency response can be predicted in sufficient accuracy. Finally, structural modification using plastic plate is discussed. The plastic plate influences to club as structural damping. The modeling to predict the effect of plastic plate is shown.