Objective: The purpose of this study was to investigate the effect of Lonicera Japonica Thunberg (LJT) on the inflammatory factor expression associated with atherosclerosis in human umbilical vein endothelial cells (HUVECs). Methods: After treatment with LJT in HUVEC which is treated with TNF-α, we measured the expression levels of biomarkers (MCP-1, ICAM-1, VCAM-1, KLF2, and eNOS), mRNA (CCL2, ICAM1, VCAM1, KLF2, and NOS3), and the proteins (MCP-1, ICAM-1, VCAM-1, KLF2, eNOS, ERK, JNK, and p38). Results: 1. Compared to the control, LJT significantly reduced MCP-1 and VCAM-1 levels at concentrations of 100, 200, and 400 ㎍/ml and ICAM-1 expression at 200 and 400 ㎍/ml compared to the control. It increased KLF2 levels at all three concentrations, but not significantly, while eNOS expression was significantly increased at 400 ㎍/ml. 2. LJT was seen to significantly reduce the expression of CCL2, ICAM1, and VCAM1 mRNA at concentrations of 100, 200, and 400 ㎍/ml compared to the control. In contrast, significantly increased KLF2 and NOS3 mRNA levels were observed at 400 ㎍/ml and at 200 and 400 ㎍/ml, respectively. 3. Compared to the control, LJT significantly reduced the protein expression of MCP-1 and VCAM-1 at 200 and 400 ㎍/ml and of ICAM-1 at 400 ㎍/ml. In addition, it increased both KLF2 and eNOS protein levels at 200 and 400 ㎍/ml. Although LJT did not have an effect on ERK expression in comparison with the control, it significantly reduced JNK levels at 200 and 400 ㎍/ml and p38 levels at 400 ㎍/ml. Conclusions: These results suggest that LJT has an effect on the inhibition of inflammatory factor expression associated with atherosclerosis in HUVECs which could contribute to the prevention of cardiovascular and cerebrovascular diseases.