Background: Endothelial dysfunction contributes to the initiation of atherosclerosis, which has been associated with the long noncoding RNAs (lncRNAs). However, the role of lncRNAs in endothelial function remains largely unknown. This study aimed to investigate whether the differentiation antagonizing non-protein coding RNA 201 (DANCR201) regulated the endothelial function. Methods and Results: The whole transcriptome sequencing was conducted to identify differentially expressed lncRNAs in the peripheral blood from patients with coronary artery diseases who had coronary calcified plaques (n=10), vulnerable plaques (n=5), and control subjects without coronary plaques (n=10). The characteristics of plaques were determined by the coronary computed tomography angiography. The results showed that DANCR201 was significantly downregulated in patients with vulnerable plaques compared to those with calcified plaques and control subjects. The RNA fluorescence in situ hybridization showed that DANCR201 was localized in both cytoplasm and nuclei. Next, we assessed the role of DANCR201 in endothelial function. In the replicative aging model of human umbilical vein endothelial cells (HUVECs), DANCR201 was found to decrease in senescent passage 20 cells compared with young passage 3 cells. Furthermore, DANCR201 overexpression in HUVECs significantly repressed monocytes adhesion to endothelium, inhibited the expression of pro-inflammatory cytokines interleukin 1β, intercellular cell adhesion molecule 1, tumor necrosis factor α, and promoted the abilities of endothelial proliferation and migration, indicating that DANCR201 was a protective factor for endothelial function. Bioinformatics analysis of miRNA-lncRNA interactions indicated that DANCR201 contained a candidate binding sequence of miR-216a which had been reported to promote the endothelial dysfunction through NF-κB pathway. The luciferase assay further showed that DANCR201 specifically combined with miR-216a. Conclusions: Our data indicated that DANCR201 can improve endothelial function via sponging miR-216a, ultimately maintaining vascular normalization. DANCR201 maybe a potential therapeutic target for atherosclerotic plaque progression and instability.