It is well known that the expression level of secretory group IIA phospholipase A2 (sPLA2-IIA) is elevated in inflammatory diseases and lipopolysaccharide (LPS) up-regulates the expression of sPLA2-IIA in human umbilical vein endothelial cells (HUVECs). Recently, lower concentration thrombin could elicit anti-inflammatory responses in HUVECs. Here, the effects of lower concentration thrombin on the expression of sPLA2-IIA in LPS-stimulated HUVECs were investigated. Prior treatment of cells with thrombin (25–75 pM) inhibited LPS-induced sPLA2-IIA expression by activating its receptor, protease-activated receptor-1 (PAR-1). And pretreatment of cells with either PI3-kinase inhibitor (LY294002) or cholesterol depleting agent (methyl-β-cyclodextrin, MβCD) abolished the inhibitory activity of thrombin against sPLA2-IIA expression. Therefore, these results suggest that PAR-1 activation by lower concentration thrombin inhibited LPS mediated expression of sPLA2-IIA by PAR-1 and PI3-kinase-dependent manner in lipid raft on the HUVECs. J. Cell. Biochem. 112: 2502–2507, 2011. © 2011 Wiley-Liss, Inc.