Objective To observe the correlation between postmenopausal estrogen levels and diabetic retinopathy (DR) in women. Methods Thirty-nine menopause female patients with type 2 diabetes mellitus and 17 menopause subjects (control group) were enrolled in this study. Control subjects aged from 53 to 82 years, with the mean age of (69.80±8.32) years. Diabetes mellitus patients aged from 56 to 84 years, with the mean age of (70.50±8.27) years; diabetes duration ranged from 3 to 23 years, with the average course of diabetes (11.40±7.97) years. DR diagnosis was according to the results of fundus fluorescein angiography, and thus the 39 patients were divided into DR group (19 patients) and non-DR (NDR) group (20 patients). There was no significant difference in age and menopause duration between the three groups (t=0.347, 0.485;P＞0.05). There was significant difference in diabetes course (t=2.748,P＜0.05). Compared with NDR group, fasting blood glucose (FBG), glycosylated hemoglobin (HbA1c), total cholesterol (TC), triglyceride (TG), low density lipoprotein cholesterol (LDL-C) were significantly increased (t=6.130, 5.322, 4.574, 2.426, 4.033), high density lipoprotein cholesterol (HDL-C) was significantly lower (t=3.917), the difference was statistically significant (P＜0.05). The level of estradiol (E2) was measured by radioimmunoassay. The differences of E2 levels between the three groups were compared. Logistic regression analysis was used to analyze the influencing factors of DR. Results The levels of E2 in control group, DR group and NDR group were (42.38±8.64), (21.49±9.81) and (32.72±10.51) pg/ml, respectively. The level of E2 in DR group was significantly lower than that in NDR group and control group (t=3.443, 10.110;P＜0.05). Logistic regression analysis showed that the duration of diabetes mellitus [coefficients =0.166, odds ratio (OR)=1.181,P= 0.016], FBG (coefficients=1.162,OR=4.014,P=0.001), TC (coefficients=3.212,OR=10.820,P=0.002), TG (coefficients=1.649,OR=5.203,P= 0.030) and LDL-C (coefficients=1.605,OR= 4.976,P=0.003) were the risk factors for DR; E2 (coefficients=−0.100,OR=0.904,P=0.004) and HDL-C (coefficients=−4.460,OR=0.012,P=0.002) were the protective factors for DR. Conclusion The estrogen level of postmenopausal women have a certain correlation with the development of DR, it may be one of the protective factor of DR.