Abstract: In order to understand the effect of exogenous androgen 17α-methyltestosterone （MT） on liver histological structure of aquatic animals, the semi-static water test was conducted using female Pesudorasbora parva as material to evaluate the effect of MT exposure on their body weight, liver weight, hepatosomatic index （HSI） and liver histology. The results showed that in early and middle phase of MT exposure, no significant changes in body weight of female Pesudorasbora parva were observed, however, in the late phase of MT exposure, their body weight were significantly reduced （P〈0.05）. The liver weight of female Pesudorcasbora parva which were subjected to exposure of different dosage MT were reduced in different degrees compared with that of CK. The change of HSI exhibited the similar trend with liver weight. In the middle and late phase of MT exposure, the HSI of female Pesudorasbora parva were significantly lower than that of CK （P〈0.05）. The histological injuries of liver after MT exposure were observed, including vacuolization and karyopyknosis of hepatocyte, and the injuries were gradually aggravated with the increase of MT dosage and extend of duration of MT exposure.