Abstract: Objective To investigate the effects and mechanisms of human placenta extracts to rats with nonalcoholic fatty liver disease.Methods Forty-two male Wistar rats were randomly divided into two groups: blank control group (n=8, fed by ordinary standard diet) and fatty-liver group (n=34, the fatty-liver models were established by feeding with high-fatty diet by a term of 12-week) .Then the fatty-liver models were randomly scarified for model group (n=8) , human placenta high dose group (n=9) , human placenta low dose group (n=9) and Essentiale group (n=8) .By the end of 4th week, histological examinations of liver were carried out with HE staining;meanwhile, the serum and tissue levels of Leptin、TNF-α、IL-6 were detected with RIA.Results The fatty degeneration in livers with low dose human placenta extracts and Essentiale were slightly milder than that of the models (P>0.05) .While high dose human placenta could obviously lessen the fatty degeneration (P<0.05) .Compared with the blank control group, the serum and tissue levels of Leptin、TNF-αand IL-6 in the model group were all remarkably increased (P<0.05) .And the human placenta and Essentiale could significantly lower the levels of Leptin、TNF–α and IL-6 (P<0.05) .There were no typical relevance between the contents of Leptin、TNF-α and IL-6 both in serum and liver tissue.Conclusion Human placenta extracts is effective in treating fatty liver disease induced by high-fatty diet.This may be due to its effects in lowering the levels of the cytokines such as Leptin、TNF-αand IL-6.