Evolution law of a negative binomial state in an amplitude dissipative channel

For the first time we derive the evolution law of the negative binomial state in an amplitude dissipative channel with a damping constant κ. We find that after passing through the channel, the final state is still a negative binomial state, however the parameter γ evolves into γ’, where γ’=γ/(e^-2κt(1-γ)+γ). The decay law of the average photon number is also obtained.