Abstract: AIMTo investigate the effects of ginkgolide B (GB) on proliferation of bovine aortic smooth muscle cells (SMC) and its related mechanisms. METHODSAfter pretreating with GB or the mixture of ginkgolide A and B (GA∶GB) at 37℃ for 0.5 h, the VSMC were treated with or without angiotensin II (Ang II) for 24 h. The proliferation of SMC was evaluated by ³H-thymidine incorporation and the cell cycle phase was measured by flow cytometry. Cytotoxicity was reflected by MTT and lactate dehydrogenase (LDH) activity of the supernatant. RESULTS Whether or not treated with Ang II, GB and GA∶GB were shown to suppress SMC proliferation in concentration-dependent fashion at concentrations ranging from 10^-9 mol·L^-1 to 10^-5 mol·L^-1. The inhibitory effects appeared to be related to a G₁→S block in cell cycle traverse. CONCLUSIONThe suppression of SMC proliferation by GB might not only be contributed by blockage of the PAF receptor activity.