UV photolysis process is little known in parts of air pollution treatment, so there are not many applications in field. Therefore we have to do more experiment and study application possibility for treatment of VOCs(Volatile organic compounds). To solve these problems, we have been studying for simultaneous application of this technology. It has shown that concentration of TCE and B.T.X., diameter of reactor and wavelength of lamp have effected on decomposition efficiency. Analysis of TCE and B.T.X. concentration was carried out by GC-FID. A cylinderical reactor consisting of a quartz tube and a centrally located lamp(ψ25mm) was used. The length and diameter of reactor were 1800mm, 75mm. It has shown that the generated ozone concentration goes up 250ppm when using 64watt ozone lamp. When using Photolysis process only, the rates of fractional conversion of each material are TCE 79%, Benzene 65%, Toluene 68%, Xylene 76%. This phenomenon can be rationalized in terms of the different bond energy that indicates how easily VOCs species can be decomposed.