A series of novel antitumor agents-the solanesylpiperazinotriamine derivatives were designed and synthesized, their structures were confirmed by IR, 1H-NMR, MS, and element analysis. The preliminary tests showed that at low micromolar concentrations these compounds exhibited obvious toxicity on tumor cells in vitro, and the synergistic effect on clinical antitumor agent indicated that at noncytotoxic concentrations they also evidently enhanced the curative effect of vincristine.