Objective To study the change of rats serum malondialdehyde (MDA) and the expression levels of 4-hydroxy acid nonene (4-HNE) and 8-hydroxy uridine (8-OHdG) of articular cartilage under low selenium (Se) and T-2 toxin poisoning,to explore oxidative damage of articular cartilage in rats.Methods Thirtytwo healthy male SD rats were divided into two groups by weight which were normal diet group and Se-deficiency group,16 rats in each group.Rats in normal diet group was fed with selenium 101.5 μg/kg diet,and rats in Sedeficiency group was fed with selenium 1.1 μg/kg diet for 30 d.Normal diet group was divided into control group and T-2 toxin group,and low selenium diet group was randomly divided into Se-deficiency group and Se-deficiency plus T-2 toxin group,8 rats in each group.After that,rats in T-2 toxin and Se-deficiency plus T-2 toxin groups were administrated intragastrically with T-2 toxin (100 mg/kg) everyday for 30 d.Rats were put to death,the left knee was taken and stained with hematoxylin-eosin and Safranin-Fast green,pathological changes of rat's knee joint cartilage were observed under light microscopy,expression levels of 8-OHdG and 4-HNE in rat's articular cartilage cells were determined by immunohistochemical method and rat's MDA content was determined by glucosinolates barbituric acid method.Results Chondronecrosis in deep zone of articular cartilage of knee joint stained with hematoxylin-eosin was seen in Se-deficient plus T-2 toxin diet group under light microscope.Significantly less Safranin-Fast green staining was observed in the cartilage of knee joints in the Se-deficient plus T-2 toxin diet group compared to the control group.Compared with control group [(3.41 ± 2.48)％,(2.28 ± 1.74)％],8-OHdG and 4-HNE in Se-deficient plus T-2 toxin group [(62.61 + 10.97)％,(75.03 ± 7.92) ％] positive expression rate increased significantly (F =16.24,18.61,all P ＜ 0.05).Comparison of serum MDA content in each group,the difference was statistically significant (F =4.32,P ＜ 0.05).The Se-deficiency group [(2.803 ± 0.163) μmol/L] was compared with control group [(1.873 ± 0.475) μmol/L] that the contents of serum MDA were increased.The T-2 toxin group [(2.890 ± 0.453) μmol/L] was compared with control group [(1.873 ± 0.475) μmol/L] that the content of serum MDA was increased (P ＜ 0.05).The Se-deficiency plus T-2 toxin group [(3.521 ± 0.292) μmol/L] was compared with Sedeficiency group and control group that the contents of serum MDA were increased (all P ＜ 0.05).Conclusions The marker of peroxidation products are increased in articular cartilage of SD rats under the condition of Sedeficiency and T-2 toxin poisoning.The cartilage damage and chondronecrosis due to Se-deficiency and T-2 toxin poisoning are related to oxidative damage.