The generation of ozone is efficient by using short high-voltage combined with a dielectric layer placed adjacent to the outer electrode in dry air. Ozone concontration depend on the peak pulsed voltage, pulse repetition rate, gas flow rate, reactor length and so on. For ozone generation by pulsed streamer discharge in dry air, a mathematical model, which describes the relation between ozone concentration and these parameters that are of importance in its design, is developed according to dimensional analysis theory. The presence of nitrogen on ozone formation in dry air cannot only consume high energy electron but also form nitrogen oxides (NOx) in discharge plasma. Nitrogen oxides (NOx) play an important role in the process of ozone generation in air discharge, where the catalytic cycle for ozone destruction takes place. So the nitrogen influencing factor should be considered. Formula is derived for predicting the characteristics of the ozone generation, within the corona inception voltage to the gap breakdown voltage. The predicted results are shown to be in good agreement with experimental findings.