The present study has performed to investigate the effects of different levels of soy phytoestrogens on gonad histological structure and E2 and P4 sex hormone levels in Yellowfin Seabream (Acanthopagrus Latus).  A total of 60 Yellowfin Seabream with an average weight of 73.70 ± 9.53 kg were divided into four groups: one control group that were feeding with standard diet without any extract and three treatment groups that received different doses of diet containing soy extract (2.5, 5 and 7.5 percent) in three replicates. Fish were fed at the rate of 3% of body weight twice a day for 14 days. Samples were taken in days of 0, 7, 10 and 14. Gonad sampling was done for histological studies and for evaluation of E2 and P4 levels, blood samples were collected from tail vein. The results showed that different doses of soy extract have various effects on gonads and in total, considering that A. latus is a protandrous hermaphroditic fish, by increasing the dose and days of exposure to soybean extract, the ovary returned to the previtellogenic state and also the appearance of testicular tissue in gonad was observed. Also, the measurement of E2 and P4 hormone levels showed that generally, decrease in  plasma E2  levels  and increase  in  plasma P4  levels was  seen  after feeding meal diets containing 2.5%, 5% and  7.5%  soy extract  in yellowfin seabream (P>0.05), which supported the findings that soybean phytoestrogens lead to endocrine disruption by different mechanisms, as shown in previous studies.