A model for atmospheric pressure glow discharge (APGD) plasmas in the nitrogen-oxygen mixtures was constructed. The model is based on electron-neutral, ion-neutral, neutral-neutral gas phase reactions and the one-dimensional fluid equations which consist of particle continuity and Poisson's equations. Optical emission spectroscopy measurements were performed for the APGD plasma at a frequency 100 kHz to evaluate the validity of the model. The emission intensity of the second positive system (SPS) band of nitrogen transition from N2(C3Πu) to N2(B3Πg) and NO-γ system transition from NO(A2Σ+) to ground state were measured as a function of mass fraction of oxygen admixture. The densities of N2(C3Πu) and NO(A2Σ+) calculated by the model show trends similar to the observed emission intensities of SPS and NO-γ system, respectively.