The iridium catalytic system composed of the [ IrHCl2( COD )]2 and the chiral diaminodiphosphine ligand was applied in the asymmetric transfer hydrogenation of 1,1-diphenylacetone in the synthesis of (S)-(-)-1,1- diphenyl -2-propanol. The influence of temperature, substrate/catalyst molar ratio, metal complex/chiral ligand molar ratio and lye concentration on the reaction was tested. The results show that 97.85% of yield and 99.35% ee were achieved when 1,1-dphenylacetone was reduced for 2 h in this catalytic system.