Enantioselective alternating copolymerizaion from carbon monoxide and styrene was carried out using cationic palladium catalyst modified by 1, 4-3, 6-dianhydro-2, 5-O-bis(benzo[1,3,2]dioxaphospholyl-2)-D-mannitol.The chiral diphosphine was proved to be effective in the enantioselective copolymerization. The pure poly(1,4-ketone)were obtained and characterized by GPC,()1H-NMR,()13C-NMR,IR and elemental analyzer.