After SUM06 and AOT40,the cumulative stomatal ozone uptake fluxes (AFstY) methods have been widely used in ozone risk assessment.But the threshold Y of the flux model cannot well reflect plant's antioxidant ability and self-repair ability to ozone exposure.How to dynamically simulate the plant's own defense mechanisms is particularly important to improve the accuracy of ozone risk assessment.This article discusses how to quantify the plant's defense against ozone based on measurement results of other researchers.The photosynthetic quantitative method is used to simulate the damage threshold dynamically and calculate the effective uptake fluxes of ozone.The SODA model is used to discuss the effect of ascorbic acid in the cell to the plasma membrane flux of ozone from two aspects of stomatal absorption and apoplast detoxification.The results provide a new perspective for ozone flux model,and lay the foundation for ozone stress effect research.