A UV light-curable organopolysiloxane composition which comprises (A) 100 parts by weight of an organopolysiloxane having at least one functional epoxy group in one molecule, (B) from 1 to 100 parts by weight of a polyether compound of the formula, R.sup.1 --(OR.sup.2).sub.n --OR.sup.3, wherein R.sup.1 represents an alkyl or alkenyl group having from 1 to 8 carbon atoms, R.sup.2 represents an alkylene group having from 2 to 4 carbon atoms, R.sup.3 represents a hydrogen atom or an alkyl or alkenyl group having from 1 to 8 carbon atoms, and n is an integer of from 1 to 50, and (C) from 0.01 to 40 parts by weight of all onium salt photoinitiator.