Containing liquid radical polymerizable monomer and (a), an organic peroxide and (b), powdered water-soluble reducing compound and (c), powdered liquid radical polymerizable monomer in (a) of nonaqueous curable composition obtained by dispersing a water-soluble reducing compound (c). According to the nonaqueous curable composition according to the present invention can be to secure the time required for bonding operation, moreover it is possible to obtain the bond strength with excellent wet body, for hard tissue of the dentin or the like in particular , industrial value of the present invention is extremely large.液状ラジカル重合性単量体(a)と、有機過酸化物(b)と、粉末状水溶性還元性化合物(c)とを含有し、液状ラジカル重合性単量体(a)中に粉末状水溶性還元性化合物(c)を分散させてなる非水系硬化性組成物が提供される。本発明に係る非水系硬化性組成物によれば、接着操作に必要な時間を確保することでき、しかも湿潤体、とりわけ象牙質等の生体硬組織に対して優れた接着強さが得られるので、本発明の工業的価値は極めて大である。
