Objective:To observe the effect of Chinese medicine freckle cream on skin superoxide dismutase(SOD), malondialdehyde (MDA) and melanin granules in male brown guinea pigs. Methods40 male brown guinea pigs were randomly divided into the blank group, model group, positive control group, Chinese medicine freckle cream group, 10 in each group. All guinea pigs were received the hair removal treatment on the back skin in an area of 3cm × 3cm once every other day. Except the blank group,the other groups were treated with ultraviolet irradiation with a wavelength of 320 nm once a day for four consecutive weeks, each irradiation time was 60 minutes, the distance between the animal and the light source was 10 cm, the skin changes in the back hair removal area of guinea pigs in each group were observed continuously. After successful modeling,the guinea pigs in the Chinese medicine freckle cream group and the positive control group were treated with corresponding drugs for external application on the skin lesions once a day,and combined with massage for 5 minutes each time. After 4 weeks of continuous administration, the animals were sacrificed by cervical dislocation and the skin tissue after the hair removal was collected rapidly. The contents of SOD and MDA in the skin of guinea pig were detected,the positive expression of melanin granules in guinea pig model of chloasma was observed by HE staining and immunohistochemical staining.  Results:The content of SOD in the Chinese medicine freckle cream group was obviously higher than that in the model group and positive control group (P< 0.05), while the content of MDA in the Chinese medicine freckle cream group was obviously lower than that in the model group and positive control group (P< 0.05), and the positive expression of melanin granules in the Chinese medicine freckle cream group was obviously lower than that in the model group and positive control group(P<0.05).  Conclusion:Chinese medicine freckle cream can improve the skin SOD activity of guinea pig model of chloasma, decrease the MDA content and reduce the generation of melanin granules in skin.