The amplitude damping model master equations of density operators unde r action of linear resonance force can be solved by virtue of thermo entangled state representation and the technique of integration within an ordered product of ope rators.We obtain the infinitive operator-sum representation of density operators with this model .Further,the evolution of excited coherent state in this model is discussed.The Wigner function evolut ion formula of excited coherent state is given.By numerical calculation,we plot the Wigner f unction.The effects of decoherence on nonclassical properties of the state are discussed.Numerical results show that the negativity area size and the depth of negativity of Wigner function decrease and until vanish with dissipation time increases.In add ition,we calculate the evolution of negative volume of Wigner function with dissipation time.We fi nd that the negative volume of Wigner function decreases with dissipation time increases.The nonclassical properties of the state are weakened and disappear with dissipatio n time increases.