The behavior of lattice oxygen species of the ferroelectric material during methane oxidation was investigated using a nonthermal plasma reactor packed with BaTiO3 pellets. Lattice oxygen species in BaTiO3 play an important role in the formation of N2O and the oxidation of CH4. The oxidation products such as CO and CO2 were formed from independent reaction pathways. Lattice oxygen species were able to preferentially oxidize the carbon species deposited on the pellet surface into CO. Also, N2O and NOx were independently formed in the N-2-O-2 reaction, suggesting that different oxygen species give N2O and NOx. N2O was produced by the oxidation of molecular nitrogen with lattice oxygen species.