Aim: To investigate antitumor indole alkaloids from the leaves and twigs of Melodinus fusiformis and M. morsei. Methods: The indole alkaloids were isolated by column chromatography and preparative HPLC. Their structures were elucidated by 1D and 2D-NMR spectroscopic methods in combination with MS experiments. Their cytotoxicity were evaluated using the MTT method in 96-well microplates. Results: Two new bisindole alkaloids, melofusine I (1) and melomorsine I (2), together with 22 known indole alkaloids 3-24, were isolated from M. fusiformis and M. morsei. All isolated compounds were tested against five human tumor cell lines, SW480, SMMC-7721, HL-60, MCF-7 and A-549. Conclusion: Compounds 1 and 2 are new bisindole alkaloids, whereas, compounds tabersonine (3) and 19. S-vindolinine (14) showed significant cytotoxicity against the above-mentioned five human tumor cell lines. © 2011 China Pharmaceutical University.