To reduce vibration effectively, optimal design of piezoelectric shunt structures was realized by analyzing the admittance of unsymmetrical smart panel . The dissipated energy in the shunt circuit is a function of admittance. Theref ore the damping effect of smart panel was evaluated by using the admittance. Fir stly, mode shapes and natural frequencies of smart panel were extracted through modal analysis. Secondly, admittance of smart panel was obtained through harmoni c analysis. Aimed at three unsymmetrical modes, the position of piezoelectric pa tch was optimized by using the first order method in the package, which makes it suppress the vibration optimally.