The properties of the square pattern as a function of the relative air content is studied in Air/Ar dielectric barrier discharge system at one atmosphere pressure. The dependence of the spatial wavelength and the traveling velocity of the square pattern on the relative air content is obtained. It is found that the spatial wavelength of the square pattern is decreased with the increased relative air content at different gas gap distances. The traveling velocity of the square pattern is also closely related to the value of the relative air content, which reaches its maximum 14mm/s when the air relative component is 10%.