At present, there is an apparent conflict between one- dimensional stratospheric photochemistry models used in predicting ozone depletion and average data for stratospheric ozone. This conflict is in three particulars-column density of O3 and ozone density in the regions around 30 km and 50 km altitude. A study of the sensitivity of one such model to the values of reaction rates, boundary conditions, solar intensities, photolysis cross sections, and O(1D) yield parameters reveals that even at the 2&sgr; uncertainty limit due to these input parameters, the model does not overlap the data for O3 density at 30 km and 50 km. The data is outside the 1&sgr; model uncertainty limit for O3 column density. The study also shows the relative contribution of the various parameters studied to the imprecision in these model results. Temperatures and eddy-mixing coefficient could substantially affect these results but are not considered in this study.