Abstract: OBJECTIVE To synthesize a series of carboline derivatives and determine their antitumor activity. METHODS 6-Substituted-α-carboline derivatives, 6-substituted-β-carboline derivatives and 3-substituted-β-carboline derivatives were synthesized through several steps from α-carboline, β-carboline and 1,2,3,4-tetrahydro-β-carboline-3-carboxylic acid separately. The antitumor activities of the target compounds were studied by MTT method. RESULTS Fifteen novel carboline derivatives were synthesized and their structures were characterized by ¹H NMR and ESI-MS. CONCLUSION All the target compounds showed antitumor activity against the tested tumor cells, some were comparable with that of taxol.