Ultraviolet (UV) radiation to mammalian skin is known to alter cellular function via generation of Reactive Oxygen Species (ROS), DNA damage and DNA lesions, such as pyrimidine dimmers and photoproducts, which could lead to DNA mutation if they are not repaired. In this study, we have investigated the reduction of DNA damage and of apoptosis with a particular attention to genetic effect of paeoniflorin in Normal Human Epidermal Keratinocytes (NHEK). After UVB irradiation from $10;to;500mJ/cm^{2}$ to NHEK, Mean Tail Moments (MTM) were increased with UVB dose increase. The greatest amount of strand breaks was induced at $500mJ/cm^{2}$ of UVB. Even at the lowest dose of UVB ($10mJ/cm^{2}$), change in MTM was detected (P<0.0001). Pretreated cell with 0.1% paeoniflorin maximally reduced the level of DNA damage to about 21.3%, compared to untreated cell. In the lower concentrations less than 0.01% of paeoniflorin, MTM had a small increase but paeoniflorin still had reductive effects of DNA damage. We measured the apoptosis suppression of paeoniflorin with annexin V flous staining kit. As we observed under the fluorescence microscopy to detect apoptosis in the irradiated cell, the fluorescence intensity was clearly increased in the untreated cell, but decreased in treated cells with paeoniflorin. These results suggest that paeoniflorin reduces the alteration of cell membranes and prevents DNA damage. Therefore, the use of paeoniflorin as a free radical scavenger to reduce the harmful effects of UV lights such as chronic skin damage, wrinkling and skin cancer can be useful to prevent the formation of photooxidants that result in radical damage.