For the first time we derive the evolution law of the negative binomial state∑n=0 n+s n γs+1(1- γ)n|n n| 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.
