Six new teleocidin-related compounds (3 ~8) together with ( -)-N^13-desmethylindolactam V (9) were found in the culture broth of Streptoverticillium blastmyceticum NA34-17 producing tumor-promoting indole alkaloids. Compounds 3 ~8 proved to be a dimer of( - )-indolactam V (3), which bound through a methylene group at position 7, 2-oxy derivatives of (-)-indolactam V (4 ~7) and 14-0-methylteleocidin A-l (8), respectively. Their tumor-promoting activities are also discussed.