High plasma levels of interleukin (IL)-$1{eta}$ and high mobility group box protein 1 (HMGB1) correlate with poor prognosis and increased mortality in patients with severe inflammation. (-)-Epigallocatechin gallate (EGCG), the main catechin in green tea, has multiple beneficial effects on reduction of inflammatory diseases; however, effects of EGCG on both IL-$1{eta}$- and HMGB1-mediated barrier disruptive responses of human umbilical vein endothelial cells (HUVECs) have not been examined. Thus, effects of EGCG on IL-$1{eta}$- and HMGB1-mediated barrier disruption in HUVECs were investigated. EGCG potently inhibited IL-$1{eta}$ or HMGB1-mediated permeability and down-regulated IL-$1{eta}$ and HMGB1-dependent adhesion and migration of THP-1 to activated HUVECs by inhibiting the activation of nuclear factor (NF)-${kappa}B$ and expression of tumor necrosis factor (TNF)-${alpha}$. EGCG inhibited IL-$1{eta}$- and HMGB1-mediated expression of cell adhesion molecules. Results showed EGCG has barrier protective activities and may represent a strategy to treat various inflammatory conditions mediated through the inhibition of IL-$1{eta}$ and HMGB1 signaling pathways.