Both photo-and redox-curabilities of dual-cured composite luting cements were investigated by infrared spectroscopy. The redox initators were effectively activated in unhardened matrices. However, it was observed that uneven cure resulting from uneven photoirradiation remained after 1 day storage at 37℃. Redox reaction was limited in gelled matrices even though their degree of conversion was low. Photo-irradiation increased the degree of conversion much more in gelled matrices than redox initiators did.It was concluded that, when uneven hardening of the luting composites by photo-irradiation is suspected, photoirradiation should be conducted after polymer matrices have gelled by redox polymerization to achieve a higher and more uniform degree of conversion.