Objective To investigate the expression level of serum microRNA-873 in patients with type 2 diabetic retinopathy and its mechanism.Methods From January 2018 to December 2019, 150 cases diagnosed with type 2 diabetes patients in our hospital were enrolled in this study as the research object. According to the presence of retinopathy, all patients were divided into group of type 2 diabetic retinopathy (DR group, n=78) and group of not retinopathy group (NDR group, n=72). The serum microRNA-873 expression, inflammatory medium and related parameters of endothelial function of the two groups were detected. Moreover, the relationship between microRNA-873 and type 2 diabetic retinopathy were analyzed. Results Compared with NDR group, the expression levels of microRNA-873, TNF-α, IL-6 and IL-17 were significantly higher in DR group (P＜0.05). Ecs level in DR group was significantly higher than that in NDR group, and EPCs level was significantly lower than that in NDR group (P＜0.05). Pearson correlation analysis showed that serum microRNA-873 was positively correlated with TNF-α, IL-6, IL-17 and percentage of Ecs (P＜0.05), and negatively correlated with PERCENTAGE of EPCs (P＜0.05).Conclusion In patients with type 2 diabetic retinopathy microRNA- 873 expression quantity change in serum, and it is related with inflammatory mediator and endothelial function.