Abstract: AimTo investigate the effect of ginkgolide B on the proliferation of VSMC and the secretion of chemokines by U937 cells stimulated by oxLDL or PAF. In addition, to analyze whether the effect of oxLDL is mediated through PAF receptor. MethodsUsing ³H-Tdr incorporation assay, the proliferation of VSMC was measured. The protein and mRNA level of MCP-1 and IL-8 in U937 cells were determined by RT-PCR and ELISA. Using Western blotting the p65 and IKB was quantified. The binding of oxLDL to U937 cell was measured by a radio-ligand binding assay of ³H-PAF. ResultsGinkgolide B inhibited, in dose-dependent manner, the proliferation of VSMC and the secretion of chemokines by U937 cells stimulated by oxLDL, and inhibited the oxLDL-induced p65 activation and depletion of IKB. oxLDL inhibited PAF binding to U937 cells. ConclusionGinkgolide B，as a PAF antagonist, possesses the effect of inhibiting the proliferation of VSMC and the secretion of chemokines by U937 cells stimulated by oxLDL in vitro. The effect of oxLDL is, at least in part, mediated through PAF receptor.