OBJECTIVE: To determine the influence of basic fibroblast growth factor (bFGF) on endothelial cell (EC) proliferation in vitro and its possible mechanisms, and to examine the effect of both TNP-470 and dexamethasone (Dex) on the EC proliferation induced by bFGF. METHODS: Human umbilical vein endothelial cells were cultured and the proliferation of EC was quantified by a colorimetric assay using MTT reagent. The expression of nuclear factor-kappa B (NF-kappa B) and ki-67 was detected with SABC immunohistochemical method. RESULTS: bFGF stimulated the EC proliferation and enhanced the expression of NF-kappa B and ki-67 in nucleus; TNP-470 and Dex suppressed EC proliferation induced by bFGF, and reduced the expression of NF-kappa B and ki-67 in nucleus. CONCLUSION: The above results indicate that the possible mechanisms of EC proliferation stimulated by bFGF come from that bFGF can activate NF-kappa B to promote the synthesis of DNA and EC mitosis. TNP-470 and Dex inhibited EC proliferation stimulated by bFGF by inhibiting NF-kappa B.