Based on the point of view of the interaction between ozone formation/destruction and solar UV energy,3 key factors of UV radiation,the absorption of UV by the substances in chemical and photochemical reactions,and the scattering of UV by aerosols etc are considered.After analyzing the observational data of ozone,solar radiation and meteorological parameters during 1990 to 1992,an empirical model for calculating total ozone amount was constructed.The calculating results agree well with observed values,and the advantage of the model is that all the data can be obtained from meteorological observation station.The monthly ozone amount from January 1979 to June 1996 in the Beijing area were calculated using this model,the calculated results are also consistent with the observed,and the maximum,minimum and averaged relative deviations between them are 15.2%,0.05% and 4.9%,respectively.The relative deviations within ±10% account for 91.4% of the total.So,this empirical model is reasonable and feasible.The decrease of ozone in the Beijing area after 1991 was related to the influence of the Pinatubo volcanic aerosols.