The work was to study protective effect of 2-selenium Bridged β-cyclodextrin (2-Se-CD), a GPX mimic, on the damages induced by moderate-wave ultraviolet rays. UVB damage model was established with murine fibroblast, NIH3T3. DAPI and MDA were used to evaluate DNA lysis rate and lipid peroxidation level respectively, Flow cytometry was used to detect production of H,2,O,2,. Significant increases were found in the DNA lysis rate, the lipid peroxidation level and the H,2,O,2, production 24 h after the treatment of 1.5 kJ m,-2, UVB. However, adding 2-Se-CD to the sample solutions could reduce all the changes to different extent. The DNA lysis rate, lipid peroxidation level and the H,2,O,2, production decreased as compared with the damage model group (,p,<,0.05—0.01). The results suggested that 2-Se-CD might protect NIH3T3 from the damage induced by moderate-wave ultraviolet rays