Atherosclerosis has become a major cause of mortality for several years, however the underlying mechanism of this disorder is still complicated. Endothelial dysfunction is a hallmark in the beginning of atherosclerosis. Lipopolysaccharides (LPS) is an important risk factor contributing to endothelial dysfunction. This study demonstrates that Halofuginone, an anti-malarial drug, possesses protective effects on human umbilical vein endothelial cells (HUVECs) against LPS-induced endothelial dysfunction. Through this study, we demonstrate that Halofuginone ameliorates LPS-induced attachment of THP-1 cells to HUVECs by inhibiting the expressions of adhesion molecules, including vascular cell adhesion molecule-1 (VCAM-1) and E-selectin. Halofuginone also suppresses the production of pro-inflammatory cytokines, including tumor necrosis factor α. (TNF-α), interleukin-1β (IL-1β), and interleukin 6 (IL-6). Furthermore, Halofuginone reduces the overproduction of reactive oxygen species (ROS) by regulating the expression of NADPH oxidase 2 (NOX-2). Mechanistically, we find the protective effects of Halofuginone depend on the expression of Kruppel-like factor 2 (KLF2), which is mediated by extracellular regulated protein kinases 5 (ERK5). Totally, our findings demonstrate that Halofuginone possesses a protective function in endothelial cells, indicating a therapeutic potential to modulate endothelial dysfunction in atherosclerosis. Copyright © 2020. Published by Elsevier B.V.