The oysters ( Saccostrea cuculiata ) were collected from four stations around Xiamen Is-land (Lundu Port, Xinglin Bay, Tong' an Bay, Huangcuo). The relation between the level ofpetroleum hydrocarbon in whole tissue and the contents of glutathione (GSH), the activity of selenium-dependent glutathione peroxidase (Se-GPx) and glutathione S-transferase (GST) in digestive gland andgill were investigated. The results showed: (1) The contents of petroleum hydrocarbon in oyster collect-ed from four stations (Lundu Port, Xinglin Bay, Tong' an Bay, Huangcuo) were 380.68, 112.34,27.31, 20.37 μg/g wet weight, respectively; (2) the activity of Se-GPx and GST in digestive glandwas lower than that in gill, and the content of GSH seemed reversibly; (3) among the four stations,both Se-GPx and GST activity of digestive gland and gill in Saccostrea cuculiata sampled from the fourstations showed a good correlation with whole tissue petroleum hydrocarbon, could be as biomarkers ofsea oil pollution.