Abstract: In order to study the subchronic toxicity of terephthalic acid and to provide basis for its health standard,SD rats were administrated therephthalic acid by oral forage at doses of 5000,500 and 50mg/kg body weight/day for 90 days consecutively.Control animals received normal feed.The biochemical parameters including ALB,AST,GTP,GGP,ALP and NAG in serum and AST,ALP,GGT,NAO,α1-MG in urine were observed dynamically.The results showed that urinary α1-MG level and NAG activity increased significantly(P<0.05) on day 30 at 5000mg/kg group,and that ALP activity got higher(P<0.05) on day 30,60 and 90 at 5000mg/kg and 500mg/kg groups,as compared with the controls.But AST showed decreasing trend at the three dosage groups. There were no obvious changes in serum parameters. These results suggest that terephthalic acid may be with a mild toxicity to kidney but without any injury to liver.