Polypeptide from Chlamys farreri (PCF) , a topical polypeptide isolated from Chlamys farreri , was used in this experiment aimed to investigate the photoprotective effect of PCF against chronic skin damage induced by ultraviolet A (UVA) and ultraviolet B (UVB) radiation. The chronic ultraviolet irradiated guinea pig model was established, and visible changes in the skin including wrinkling, sagging and erythema were observed. Malondialdehyde (MDA) and antioxidant enzymes including superoxide dismutase (SOD) and glutathione peroxidase (GSH px) in the dorsal skin were determined using biochemical methods. The results showed:(1)PCF (5 % and 20%) could greatly protect the dorsal skin of guinea pig against wrinkling, sagging and erythema induced by UV radiation in a concentration dependent manner.(2)PCF could reduce MDA formation in the dorsal skin caused by UV irradiation, while increasing the activities of SOD and GSH px.(3)The differences among the PCF groups and UV model group were significant ( P <0.05, P <0.01). These results indicated that topical application of PCF provided broad solar UV spectrum photoprotection; and that the antioxidant property of PCF might play a role in photoprotection. Polypeptide from Chlamys farreri (PCF), a topical polypeptide isolated from Chlamys farreri, was used in this experiment aimed to investigate the photoprotective effect of PCF against chronic skin damage induced by ultraviolet A (UVA) and ultraviolet B (UVB) radiation. The chronic ultraviolet (MDA) and antioxidant enzymes including superoxide dismutase (SOD) and glutathione peroxidase (GSH px) in the dorsal skin were determined using biochemical methods. The results showed: (1) PCF (5% and 20%) could substantially protect the dorsal skin of guinea pig against wrinkling, sagging and erythema induced by UV radiation in a concentration dependent manner. formation in the dorsal skin caused by UV irradiation, while increasing the activities of SOD and GSH px. (3) The differences among the PCF groups and UV model gro These results indicated that topical application of PCF provided broad solar UV spectrum photoprotection; and that the antioxidant property of PCF might play a role in photoprotection.