Calculations of reactions about the chemistry of nitric oxides and ozone were performed to study the effect of NO_X emission in the stratosphere. They were conducted with parameters in the stratosphere. In addition, sensitivity analysis was performed to study the mechanism of their reactions. Measurements of NO_X under an emission of a low-pressure mercury lamp were also conducted by NO and NO₂-LIF method experimentally. A large evacuable chamber was used to simulate stratospheric condition. Numerical results and experimental ones were compared and chemical and photochemical reactions of NO_X -ozone chemistry were discussed. As results, main reactions of ozone depletion by NO_X and HO_X were specified and simulation of reactions in the stratosphere was achieved qualitatively by laboratory-scale experiment.