Photon-added chaotic field is constructed by creation operator roling in chaotic field.Nonclassical property and decoherence of photon-added chaotic field are analysed.Master equations of density operators can be concisely solved by the technique of integration with in an ordered product of operators and virtue of thermo-entangled state representation.We get the evolution formula of the field density operator which is in photon-added chaotic field initially.The evolutions of its Wigner function and the evolutions of P representation are given.The nonclassical property is discussed by calculating its Wigner function in phase space.Numerical results show that the photon-added chaotic field displays nonclassical property initially, and its nonclassical property is weakened with dissipation time increasing.On the other hand, its nonclassical property is also weakened with added photon number increasing.