Objective: To study the correlation between Erα gene polymorphism and the distribution pattern of TCM meridian syndrome in women with knee osteoarthritis. Methods: A total of 120 Knee osteoarthritis (KOA) female patients admitted to our hospital between January 2018 and December 2018 were selected as the observation group, and 120 healthy female subjects accepted physical examination at our hospital over the same period were selected as the control group. The Erα gene distribution of estrogen receptor was compared between the two groups to identify the differences between KOA women and healthy women. The TCM syndromes and meridians types of the patients in the observation group were defined to evaluate the degree of KOA. The correlation among KOA status, Erαgenotypes, TCM syndromes and meridians was analyzed. Results: The distribution of Erα gene XbaI was significantly different between the observation group and the control group (χ²=35.339, P<0.001). There was a statistical difference in the distribution of XbaI genotypes between mild to moderate and severe patients in the observation group (χ²=29.088, P<0.001). There was a moderate correlation between the Lequesne score and the fascia type in KOA women, and a high correlation between the Lequesne score and the TCM syndrome differentiation type, and a moderate correlation between the Lequesne score and the Erα gene and the XbaI genotype (P<0.05). The Erα gene polymorphisms, meridians and syndrome differentiation were moderately correlated (P<0.05). Conclusions In female patients with knee osteoarthritis, the conditions are more serious in patients with complex type of tendons, deficiency of liver and kidney, phlegm and blood stasis, Erα gene xx genotype, and there is a clear correlation between the TCM type of tendons and ER gene polymorphism.