In case of injection of neutral gases into ionosphere, atomic oxygen ions undergo charge transfer reactions with these injected molecules. The recombination rate coefficients of molecular ion with electron are several orders greater than that of the dominant atomic oxygen ion in ionosphere F region. Therefore, rockets exhaust gases produced by engine and artificially released neutral gases in the space active plasma experiments can substantially affect ionosphere, for example, the formation of electron depletion region, which is referred to as ionospheric holes, and these phenomena have been observed in many experiments. In this paper, in terms of diffusion equation of neutral gas in thermosphere and main ion-chemistry reactions in ionospheric F region, the diffusion processes of H2, H2O and CO2 and ionospheric response to released gases are investigated. Additionally, airglow volume emission rates and intensity from the release at ionospheric altitudes are calculated The results show that the diffusion of released neutral gas in F region is very quick, and these gas molecules can cause a large-scale depletion of ionospheric electron density. At some altitudes of F region, the dominant positive ion converts into other molecular ion, such as H2O^＋. During the diffusion process, airglow will be excited, and its wavelength and emission characteristics depend on the released materials.