Objective: To compare the hepatoprotective effect of Dicliptera chinensi polysaccharide (DCH) with different molecular weight on carbon tetrachloride -induced acute liver injury in rats and its possible mechanism was evaluated. Method: Seventy male Sprague-Dawley rats were randomly divided into model

biphenyl dimethyl dicarboxylate treated group

the total polysaccharide of DCH treated group (Group A)

the polysaccharide of DCH treated groups (Group B

Group C

Group D

which molecular weight is<6 000

6 000-10 000

>10 000)and normal control group. It should be lavaged during 7 day before established the model of Group A(250 mg·kg-1)

Group B(250 mg·kg-1)

Group C(250 mg·kg-1)

Group D(250 mg·kg-1) and biphenyl dimethyl dicarboxylate treated group(250 mg·kg-1)

while other groups were controlled by administration of normal saline.One hour after the final intragastric administration

all rats apart from the rats in the normal control group were lavaged with 0.01% ip carbon-tetrachloride(CCl4) with peanuts oil(10 mL·kg-1) according to establish the model of acute liver injury in rats

while other groups were controlled by administration of normal saline.To detect the ALT

AST and TPA

serum sample were collected after 16 hours by aorta sampling. Result: Compared with the normal control group

the AST

TP and ALT in serum of rats in model group were significantly increased (P<0.01).The content of TP was reduced by the total polysaccharides of D. chinensis(the A group)(P<0.05 or P<0.01). The SOD activity was obviously increased by the molecular weight<6 000 group(the B group)(P<0.01). The GSH-Px activity was increased by the A group and the molecular weight 6 000-10 000 group(the C group)(P<0.01).Necrosis and passive congestion of hepatic tissue in model group were numerous.The injury of hepatic tissue were inhibited in different polysaccharide of DCH treated groups while the optimum effect is in Group B.The optimum effect of hepatic index appeared in Group D. Conclusion: It was significant that the inhibition of hepatic injury in the polysaccharide of DCH which had different molecular weight treated groups while the effect was the best when molecular weight<6 000.