Abstract: Drinking alcohol during pregnancy resulted in a series of developmental abnormalities.To explore its mechanism,this study used the integer animal model to investigate the effects of alcohol on uterus embryonic development in organic orphog enesis.Immunohistochemistery and enzyme histochemistry technique were used to research expression of the activity of nitric oxide synthase and neuronal nitric oxide synthase in hippo campi.The result showed that the dose of 1.0g/kg/d of alcohol could rise to the characteristic of fetal alcohol syndrome.Alcohol could lead to the activity of NOS and nNOS increasing.It is suggested that NO products would be heig htened in brain.These results illuminated that alcohol possesses developmental toxicity.The effects of alcohol gave rise to abnor malities of embryonic brain development that may be related to NO increasing.