To investigate the alkaloid constituents of Gelsemium elegans Benth. and evaluate their cytotoxic,the alkaloid constituents were separated and purified by chromatographic techniques,including column chromatography of silica gel,MCI-gel,Sephadex LH-20 and HPLC.Their structures were mainly elucidated by NMR and MS spectroscopic techniques.Nine indole alkaloids were isolated and purified from the roots and stems of Gelsemium elegans Benth.,they were identified as gelsemine(1),koumine(2),humantenine(3),gelsevirine(4),19-(S)-hydroxydihydrogelsevirine(5),koumidine(6),19-(S)-kouminol (7),19-(R)-kouminol(8),gelsenicine(9).The antitumor activity of the isolated compounds was detected by MTT assay.Compounds 1-3 exhibited significant cytotoxic activity against HepG2 cancer cells,with IC₅₀ values of 10.02±0.16,3.98±0.11 and 9.87±0.18 μM respectively.