Abstract: In order to study the influence of exogenous hormones on the sex differentiation of tilapia,the New Gift Tilapia(Oreochromis niloticus)was induced by oral and soating estradiol benzoate as the exogenous estrogen.By setting different drug concentration gradients and induction durations,the effects of two methods of inducing feminization,both oral and soating,on the feminization of tilapia of the Gift Tilapia were studied.The results showed that during the induction of feminization with different drug concentrations,the female rate increased with the increase of concentration and the induction days,and there was a significant difference from the control group(P<0.05).The highest female rate in the 150 mg/kg feed treatment group for 90 days was 94.45%,which was 49.34% higher than that of the control group(46.11%),and the lowest female rate was 65.00% in the 50 mg/kg group after 30 days of feeding.During the induction of feminization for 30 days by soating with different drug concentrations,the female rate increased with the increase of bath concentration,and they were significantly higher than the control group(P<0.05).The highest female rate was 77.78% in the group with 150 μg/L.The above results indicated that both oral and bathing female methods had good effects on inducing sex conversion of the Gift Tilapia,but considering the effectiveness and convenience,it was suggested that oral methods was easier to induce and obtain feminization fish.