Laboratory measurements of the charge transfer reaction of N2+ (X, 2&Sgr;g+, &ngr;≠0) and N2+ (X, 2&Sgr;g+, &ngr; = 0) with O2 have been carried out with various mixtures of these N2+ species in the energy range from near thermal to 0.12 eV. No difference in the reactivities of vibrationally excited and nonexcited N2+ (X)-both present in the ionosphere-with O2 was observed.