Study the anti-androgenic effect of diethylhexyl phthalate (DEHP) and dibutyl phthalate (DBP).Methods According to Hershberger bioassay form OECD guideline, 6 weeks old male castrated SD rats were randomly divided into 16 groups, DEHP (35,0, 150,0, 500,1 000 mg/kg BW) and DBP (70,0, 250,0, 750,1 000 mg/kg BW ) were given by oral gavage, respectively. Meanwhile, corn oil was given by oral gavage as a negative control, and 3.0 mg/kg BW flutamide was given by oral gavage as a positive control for 10 consecutive days. In addition, 0.2 mg/kg BW testosterone propionate was given to each group by subcutaneously inject before gavage. In the end of test, animals were anesthetized, weight of glans penis, ventral prostate, seminal vesicles, levatorani-bulbocavernosus muscles, Cowper's glands were measured, testosterone and luteinizing hormone levels were measured. The dose-response were analyzed by benchmark does software. Results In comparison with negative control, weight of ventral prostate, levatorani-bulbocavernosus muscles and Cowper's glands were significantly decreased in the group of 250,0 and 1 000 mg/kg BW DEHP (P<0.05) , and weight of levatorani-bulbocavernosus muscles and Cowper's glands were significantly decreased in the group of 500,0 and 1 000 mg/kg BW DBP (P<0.05). Benchmark does of DEHP and DBP was 150.38 and 276.78 mg/kg BW.Conclusion DEHP and DBP had anti-androgenic effects in vivo and weight of levatorani-bulbocavernosus muscles and Cowper's glands are sensitive indexes.