Abstract: Objective 　To study the effect of pyrrolidine dithiocarbamate ( PDTC), a potent inhibitor of nuclear factorκB (NF-κB) activation, on the growth and angiogenesis of human lung cancer xenografts in nude mice. Methods 　A549 cells were incubated and were inoculated subcutaneously in athymic nude mice to establish xenograf t models. The mice were divided into control group and PDTC group. The inhibitory rate was calculated according to the weight s of xenografts. Cyclooxygenase 2 (COX-2) mRNA was measured by semiquantitative reverse transcription-polymerase chain reaction ( RT-PCR) analysis. The proteins expressions of vascular endothelial growth factor (VEGF) and F Ⅷ were assessed by immunohistochemical method, and MVD was counted according to F Ⅷ staining. Results 　The weight of xenografts was significantly lower in PDTC group than that in control group ( P < 0. 01) and the inhibitory rate was 41. 03 %. The expressions of COX-2, VEGF and MVD count of xenografts were significantly decreased in PDTC group than that in control group ( P < 0. 01, P < 0. 01, P < 0. 05) . Conclusion 　PDTC can inhibit the growth of human lung cancer xenografts in nude mice, which may be due to the downregulation of COX-2 and VEGF thus inhibit tumor angiogenesis.