Ornithine decarboxylase (ODC), the first enzyme in the polyamine biosynthesis, plays an important role in tumor progression, cell proliferation and differentiation. In recent years, ODC has been the subject of intense study among researchers, as a target for anti-cancer therapy and specific inhibitory agents, have the potential to suppress carcinogenesis and find applications in clinical therapy. In particular, it is suggested that ODC is a promising candidate target for natural products in cancer chemoprevention. Future exploration of ornithine decarboxyalse inhitors present in nature may offer great hope for finding new cancer chemporeventive agents.