A light-sensitive composition containing a polymerizable compound having at least one ethylenically unsaturated group, and a photopolymerization initiator of general formula (I): ##STR1## wherein Y represents --COOR.sub.1, ##STR2## --R.sub.3 --COOR.sub.1, --R.sub.3 --CONHR.sub.1 or --NHCO--R.sub.4 (wherein R.sub.1 represents a hydrogen atom, an alkyl group, or an aryl group; R.sub.2 represents a hydrogen atom or a methyl group; R.sub.3 represents an alkylene group; R.sub.4 represents an alkyl group, an alkoxy group, an aryl group; and l and m respectively represents integers of 1 to 10.); Ar represents a phenylene, naphthylene or heterocyclic aromatic group; X represents a chlorine atom or a bromine atom; and n represents 1 or 2.The light-sensitive composition has a good stability over time since crystallization of the photopolymerization initiator on the surface of the light-sensitive layer is inhibited.