The kinetics of stratospheric sulfuric acid aerosols accumulation is modeled. The chemical scheme includes 10 main reactions of the oxygen cycle of ozone and SO2 photo-oxidation. Accounting of SO2 photo-oxidation by the ozone is the peculiarity of this scheme. This reaction proceeds with participation of triplet excited SO2 molecules, its rate constant being equal to approximately 10-12cm3s-1. Satisfactory agreement between calculated and experimental temporary variations of sulfuric acid aerosols concentration was obtained.