Objective To establish a rat model of portal hypertension and explore the relationship between the angiopoietin-1(Ang-1)/tyrosine kinase receptors 2(Tie-2) system and the neoangiogenesis in lower esophagus of rats with portal hypertension. Methods Fifty SD rats were randomly divided into two groups:experimental group(thirty rats, partial portal vein and left suprarenal vein were ligatured to make portal hypertension model) and control group(twenty rats, the portal vein and left suprarenal vein were separated but not ligatured). The lower esophageal tissue was obtained two weeks after the operation.The immunohistochemical streptavidin-perosidase(SP) technique was used to detect the expression of Ang-1, Tie-2 and CD34.The microvessel density (MVD) was determined by CD34 staining.The relationship between Ang-1, Tie-2 and the neoangiogenesis in lower esophagus was analyzed after that. Results The models of portal hypertension were set up successfully in 37 rats(17 in experimental group and 20 in control group).Compared with those of control group, the differences in the expression of Ang-1, Tie-2 and MVD were statistically significant(P 0. 05), but the expression of Tie-2 was positively correlated with MVD(r= 0. 71, P< 0. 05). Conclusion The expression of Ang-1, Tie-2 and MVD is obviously higher in lower esophagus of rats in experimental group than that in the control group.The Ang-1/Tie-2 system is possibly related to the neoangiogenesis in lower esophagus of rats with portal hypertension. Key words: Portal hypertension; Angiopoietin-1; Tyrosine kinase receptors 2; Microvessel density