Objective To investigate the expression and the roles of Angiopoietin 1(Ang-1) and Angiopoietin 2(Ang-2) in the endometrium of women with abnormal bleeding after medical abortion. Methods Analyzing endometrial pathological change of 1087 patients with abnormal bleeding after medical abortion in early pregnancy,and the endometrial specimens from 40 patients were randomly chosen for the study. The endometrial specimens from 20 women without abnormal bleeding after medical abortion were used as control group.Immunohistochemistry was used to detect the levels of Ang-1 and Ang-2 proteins in endometria. Results The percentage of patients with both the residul decidua and villus was 80.5%; positive immunoreactive signals of Ang-1 and Ang-2 were found in the endometrial glandular epithelium, stromal cells and the endothelial cells of vessels; the expression rate of Ang-1 and Ang-2 in the patients with abnormal bleeding were higher than that in the control group（P<0.01）.Conclusion The residul decidua and villus are probably the main cause of abnormal bleeding after medical abortion.The hyperexpression of Ang-1 and Ang-2 in the endometrium of patients with abnormal bleeding after medical abortion may play an important role in the process