Abstract: Objective The aim of this study is to explore the effect of lipopolysaccharides on hepatic vascular pathologic changes in chronic hepatitis B.Methods 120 cases of patients with chronic hepatitis B were classified by hepatic vascular pathologic changes.Normal liver tissue of 10 healthy persons were chosen as the control group.The serum LPS levels in cases were quantitatively determinated with enzyme linked immunosorbent assay（ELISA）.The expression of TLR4 was determined by immunohistochemical staining.The results were evaluated by integrative index.Result ①The serum LPS levels in healthy controls were very low（0.30±0.13ng/ml）.The serum LPS levels of patients with hepatic vascular lesions grade 1 were 0.32±0.14ng/ml.There was no signifiant difference in the serum levels between patients of hepatic vascular lesions grade 1 and normal controls（P>0.05）.The serum LPS levels of patients with hepatic vascular lesions grade 2 and grade 3 were 0.71±0.14ng/ml and 1.10±0.15ng/ml respectivity,which were significantly higher than those of normal controls（P<0.01）.There was a positive correlation between serum LPS level and the grade of hepatic vascular lesions （r=0.892,P<0.01）.②The intensity of TLR4 expression in liver tissue of chronic hepatitis B was significantly higher than that of health control（P<0.05）.The positive staining was mainly located on cell membrane and some in cytoplasm.In chronic hepatitis B,the intensities of TLR4 were positively correlated with the grade of hepatic vascular lesions（r=0.728,P<0.01）．Conclusions LPS and its receptor TLR4 might play an important role in hepatic vascular pathologic changes.The serum LPS level can be used as one of indexes to predict the severity of hepatic vascular lesions.

Key words: Hepatitis B, Lipopolysaccharides, Toll-like receptor 4, Blood vessels