Abstract: Objective To study the antagonism of hydroxytyrososl(HT) on male reproductive toxicity induced by perfluorooctane sulfonate(PFOS).Methods Totally 50 male mice were randomly divided into five groups:control group,PFOS group(25.0 mg/L),PFOS(25.0 mg/L) plus low-dose HT(12.5mg/L),PFOS(25.0 mg/L) plus midium-dose HT(25.0 mg/L),and PFOS(25.0 mg/L) plus high-dose HT(50.0 mg/L) groups.After the animals were fed with deionized water supplemented with PFOS or/and HT for 35 days,the count of sperm and the rates of spermmobility and aberration were analyzed;the levels of lactate dehydrogenase(LDH),alkaline phosphatase(ALP),serum testosterone(T),and luteinizing hormone(LH) were examined;meanwhile catalase(CAT),superoxide dismutase(SOD) enzyme and the change of malondialdehyde(MDA) content were detected.Results The number of sperm in rats of low,medium,and high dose of HT groups increased significantly(21.01,22.76,and 23.76 ?10⁷/g epididymis) compared with that of PFOS exposure groups.In addition,the sperm motility increased(55.24%,71.03%,and 83.19%) and the sperm deformity rate decreased.The levels of LDH,ALP,serum T,and LH of medium and high HT groups increased(P<0.05 for all) compared to those of PFOS group.The low,medium and high doses of HT recovered the activities of SOD and CAT enzyme,lowered MDA content obviously compared with PFOS groups,with significant differences(P<0.05 for all).Conclusion HT can inhibit the damage of reprouductive function induced by PFOS.Reducing oxidative damage and regulating secretion of testosterone and LH are important mechanisms of the effect.