Objective:To discuss protective effect of different extractions of two origin Bupleurum longicaule var.giraldii on acute liver injury in mice caused by intraperitoneal injection(ip)D-galactosamine, and to screen the optimum process and the active site of extraction. Method: The mice were divided into 9 groups: control group, model group, galactosamine group,bifendate group (150 mg·kg^-1), water extraction group,65% ethanol extract group,95% ethanol extract group of B. longicaule var.giraldii sample No.1 and No.2, delivery 20 mL·kg^-1 by intragastric administration(ig).Model group and control group were given normal saline by ig once a day with the same dose. After continuous administration of 7 days, model of mice were made by intraperitoneal injection of D-galactosamine hydrochloride solution, and after 16 hours, ocular venous blood were collected to determine the serum alanine aminotransferase(ALT)and aspartate aminotransferase(AST)activities and the malondialdehyde(MDA)content and superoxide dismutase(SOD)activity in liver homogenate. Result: Two origin of B. longicaule var.giraldii on aqueous extraction group, 65% ethanol group and 95% ethanol group showed that they all could decrease the serum ALT and AST activity in model, reduce the content of liver MDA and increase the SOD activity, and the 65% ethanol extract of B. longicaule var.giraldii gathered from East Taibai Mountain had the strongest effect (P<0.01, P<0.05). Conclusion: B. longicaule var.giraldii has obvious protective effect on D-galactosamine hydrochloride induced acute liver injury in mice. There is a dose-effect relationship between its hepatoprotective effect and saikosaponin a, d content.