The aromatase enzyme is an enzyme that converts testosterone to estrogen. This means that by administering aromatase blockers, testosterone levels increase and estrogen levels decrease. The problem faced is how the spermatogenesis process occurs because estrogen is needed as well in the process. This study aimed to evaluate the histopathological features of the testes due to the administration of natural aromatase blockers (NAB). Fifteen male Bangkok chickens were divided into 5 groups, namely: control group (C); testosterone continues (Tc 0.4 mg/bird/day); natural aromatase blockers 33 (NAB 3.3 g/bird); natural aromatase blockers 66 (NAB 6.6 g/bird); zinc (Zn): 0.45 mg/kg body weight (BW). The oral treatment was given for 35 days. The results showed that NAB did not affect wattle growth, but significantly affected testicle weight (p-value < 0.05). The NAB 66 group had the heaviest testis weight, followed by zinc, continuous testosterone, NAB 33 group, and the control group. This results was confirmed by HE staining on the testes which showed the thickness of the thickest spermatogenic and spermatid cell layers in the NAB 66 group. It was concluded that giving NAB did not harm the spermatogenesis process.