Abstract: Objective To study the protective effects of astaxanthin liposome (Asx-lipo) on photodamage by UVB in mice skin. Methods 40 C57BL/6J mice were randomly divided into four groups: The blank group (no irradiation, no drug use), model group (UVB light injury group, no drug use), control group (irradiation + astaxanthin), experimental group (irradiation + astaxanthin liposome), each group with 10 mice. Each group was given the corresponding light (the radiation intensity was 2 mW·cm², the time of irradiation was 60 s, 1 times a day for the first 5 days, and 1 times every other day for the next 9 days, 10 times in a total of 2 weeks.) and drug intervention (topically treated with 4 mL 0.2‰ astaxanthin or 4 mL 0.2‰ Asx-lipo 10 min before the irradiation) for two weeks. After that, samples were examined by the following indicators: the histological changes of skin, Ki-67, 8-hydroxy-2′-deoxyguanosine(8-OHdG), superoxide dismutase(SOD) activities and serum matrix metalloproteinase-13 (MMP-13). Results HE staining the model group and the control group showed that the dermis became thin, the dermal collagen fibers were long and thin, and the arrangement was loose and disordered. Compared with the blank group, the expression of Ki-67, MMP-13 and 8-OHdG increased and SOD activity decreased, and the differences were statistically significant (P<0.05). Compared with the model group, the pathological changes of skin tissues in the experimental group were significantly improved, with decreased expressions of Ki-67, MMP-13 and 8-OHdG and increased SOD activity, and the differences were statistically significant (P<0.05).Conclusion The photodamage of mice skin can be improved by topical Asx-lipo. The mechanism may be related to the strong antioxidation of Asx-lipo.