A zero-dimensional model is used for studying the behavior of main particle species in atmosphere plasmas with different ionization degrees. The electron lifetimes are obtained for different initial density in an afterglow plasma, and the temporal evolutions of the main charged and neutral species are presented. The results show that the electron number density decays fast, and the lifetimes decrease with ionization degree increasing. Some important neutral species such as O, N, O3 and NO are also analyzed with ionization degree increasing.