Radical polymerizable composition and lithographic printing plate precursor using the same

A lithographic printing plate precursor comprising a support having thereon a recording layer comprising a radical polymerizable composition comprising (A) an alkali-soluble resin containing a radical polymerizable group, (B) a polymerizable compound, and (C) a radical initiator, wherein reactivity between the polymerizable compounds (B) is larger than reactivity between the polymerizable compound (B) and the alkali-soluble resin (A) containing a radical polymerizable group, and the reactivity between the radical polymerizable composition comprising (A) an alkali-soluble resin containing a radical polymerizable group, (B) a radical polymerizable compound, and (C) a radical initiator, wherein reactivity of a polymerizable group of the polymerizable compound (B) to a polymerizable group of the polymerizable compound (B) is larger than reactivity of a polymerizable group of the polymerizable compound (B) to a radical polymerizable group of the alkali-soluble resin (A), and a reactivity of a radical polymerizable group of the alkali-soluble resin (A) to a polymerizable group of the polymerizable compound (B) is larger than reactivity of a radical polymerizable group of the alkali-soluble resin (A) to a radical polymerizable group of the alkali-soluble resin (A).