A curable composition comprising: (A) 100 parts by mass of a monomer component which comprises a radically polymerizable monomer and has a water absorbing capacity of not larger than 20% by weight; (B) 0.5 to 10 parts by mass of water; (C) 0.1 to 20 parts by mass of a surfactant; and (D) an effective amount of a radical polymerization initiator. The curable composition is cured by polymerization in a state where a water layer is formed on the surfaces of the cured body that is being formed, effectively suppressing the hindrance of polymerization caused by oxygen and decreasing the formation of unpolymerized product on the surfaces of the cured body. The curable composition is particularly useful as a dental restorative which involves difficulty when it is to be polymerized while shutting off oxygen.