Objective To explore the relationship between pathological changes of liver,serum ALT,expression of P-selectin in serum of mice and different dose of venom,the poisoning time induced by Agkistrodon Halys Pallas venom.Methods Using two -factor factorial design,72 male Kunming mice of clean grade were randomly ( random number) divided into 9 groups (n =8).As per the different doses of snake venom injected and different lengths of time after venom injected,the 9 groups were 0-dose (0.0 mg/kg) 3 hours after saline given group,0-dose 8 hours after saline given group,0-dose 24 hours after saline given group,low-dose (0.5 mg/kg) 3 hours after venom given group,low-dose 8 hours after venom given group,low-dose 24 hours after venom given,high-dose ( 1.0 mg/kg) 3 hours after venom given group,high-dose 8 hours after venom given group and high-dose 24 hours after venom given group.The pathological change of liver tissue was determined,and ALT and expression of P-selectin in serum were detected.Results In the venom given groups,the liver histopathologic scores,serum ALT value and expression of Pselectin in serum were significantly higher than those in control group ( P ＜ 0.05 ),and those in high-dose group were higher than those in low-dose group (P ＜ 0.05 ),and those in 8h groups were higher than those in 3h groups (P＜0.05),and those in 24 h groups were higher than those in 8 h groups (P ＜0.05).As the dose of venom increased and the length of time after venom given extended,the liver histopathologic scores,serum ALT and expression of P-selectin in serum were higher.A positive correlation between Pselectin expression and liver histopathologic scores was found after correlation analysis ( r =0.98,P ＜0.05 ).Conclusions Agkistrodon snake venom can cause acute liver injury with elevated ALT and Pselectin in mice.As higher dose of venom given and longer length of time after venom given extended,more serum ALT and P-selectin are produced.Between acute liver injury and high expression of P-selectin exists a correlation,suggesting overexpression of P-selectin is one of the mechanisms of acute liver injury induced by Agkistrodon Halys Pallas venom.