Visible　light-regulated　organocatalytic　polymerization　has　attracted　considerable　attention　in　recent　years　due　to　its　mild,　metal-free　reaction　conditions　and　the　capability　of　mediating　polymerization　with　spatial　and　temporal　controls.　Here,　we　report　the　successful　identification　of　hydroxybenzophenones　(BPOHs)　as　an　effective　class　of　photoacid　catalysts　for　the　ring-opening　polymerization　of　lactones,　which　could　afford　biodegradable　polyester　products　with　predictable　molecular　mass　and　low　dispersity　under　the　irradiation　of　visible　light.