Objective To investigate the effect of 1 800 MHz electromagnetic radiation on activity of SOD and GSH－Px in the skin tissues of SD rats.Methods A total of 98 healthy SD rats with SPF level,aged 4 weeks, were randomly divided into radiation group and control group.The radiation group was totally exposed under 1 800 MHz electromagnetic wave with seven different power density of radiation of 0.1 mW/cm2,0.3 mW/cm2,0.5 mW/cm2 , 0.7 mW/cm2, 0.9 mW/cm2, 1.0 mW/cm2and 1.2 mW/cm2respectively.It lasted 21 days and for a period of 12 hours a day. After radiation,the activity of SOD and GSH－Px in the skin tissues were detected by enzyme marker. Results In radiation group,the activity of SOD and GSH－Px in the skin tissues of SD rats were decreased under 0.3 mW/cm2and 0.5 mW/cm21 800 MHz electromagnetic wave. Compared with the control group, there was a significantly difference in radiation group (P＜0.05) .While under other four 1 800 MHz electromagnetic waves, the activity of GSH－Px and SOD in the skin tissues showed no statistical difference between the two groups (P＞0.05) . Under 1 mW/cm21 800 MHz electromagnetic wave, the activity of GSH－Px showed no statistical difference between two groups (P＞0.05) . Conclusion The power density of 0.3 mW/cm2and 0.5 mW/cm21 800 MHz electromagnetic wave can reduce the activity of GSH－Px and SOD in the skin tissues of rats.