Cell culture was carried out to investigate whether the protective and repairing capacity of SOD against the radiation damage induced by UV-C was improved because of its transduction ability. When L-02 cell line being exposed to UV-C in the solution with SOD enzymatic activity of 320U/mL, the protective rate of PTD-SOD increased to 58.5% , which was about 5 times of that of wild-type SOD; when irradiation duration prolonged to 140s, the protective rate of PTD-SOD remained to be 43.2%, while that of wild-type SOD was almost undetectable. Regarding restorative rate, that of PTD-SOD could reserve 50.1% when L-02 cell exposed to UV-C for 40s, while that of wild-type SOD was less than 8%. These results suggested PTD enhanced the protective and repairing ability of SOD against UV radiation remarkably, owing to improve bioavailability of SOD.