Anti-oxidative, anti-tumor-promoting, and anti-carcinogenic activities of adonirubin and adonixanthin, which are biosynthetic intermediates from β-carotene to astaxanthin, were investigated. Both adonirubin and adonixanthin showed almost the same activities for inhibition of lipid peroxidation and quenching of singlet oxygen as those of astaxanthin. Furthermore, adonirubin and adonixanthin exhibited an inhibitory effect on Epstein-Barr virus early antigen activation in Raji cells and carcinogensis of mouse skin tumors initiated by 7,12-dimethylbenz[a]anthracene and promoted by 12-O-tetradecanoylphorbol-13-acetate.