Abstract:Objective: To explore the liver-toxic fraction in Rhigoma of Dioscorea bulbifera. Method: The rats were randomized into four groups: control group (20%PVP-water) , T001(10% total methanol extraction), F002(5% chloroform fraction) and F003(5% methanol fraction). Direct bilirubin (DBil) and Glutamic-pyruvic transarninase (GPT) were examined, and liver index was measured. The histological and morphological observations were performed with optical and electrical microscope. Result: T001 and F002 showed significant liver toxicity. Conclusion: The chloroform fraction was the liver-toxic fraction of D. bulbifera .