AbstractAccording to the plasma theories, the temperature and electron density are calculated based on the wavelengths, relative intensities and transition parameters of lines in cloud lightning spectra which have been obtained on the Tibetan plateau. By using Saha equations, electric charge conservation equations and particle conservation equations, the particle densities in every ionized‐state, the mass density, pressure and the average ionizability of discharge channel are obtained. Moreover, the characteristics of particle distributions in each discharge channel are analyzed. The results show that cloud lightning channels are almost completely ionized, and the most particles are singly ionized while NII has the highest particle density. In general, the particle densities and relative concentrations of different channel positions also have positive correlations with temperatures except for NII, OII and ArII, of which relative concentrations show tiny tendencies of becoming low along with the temperature increasing. Differing from cloud‐to‐ground lightning, the particle densities of different positions along the same cloud discharge channel change in a bigger range but show no regularities. The pressures of channels change from a few tenths of one MPa to several MPa.