The effects of TNP-470, one of the promising antiangiogenic agents and taxol when combined were evaluated in two human cultured cell lines derived from non-small cell lung cancer(NSCLC). Cytotoxicity was determined using a tetrazolium salt(MTT) assay. The inhibitory effects of TNP-470 on cell proliferation were dose related and the 50% inhibitory concentration on these cell lines were 50.0 to 62.5 microM. Evaluation of drug interactions with isobologram and the combination index values showed that sequential exposure to taxol followed by TNP-470 produced synergistic effects in these cell lines tested. Our findings suggest that such an angiocytotoxic chemotherapy might be promising for the treatment of NSCLC.