A kinetic system correlating the enantioselectivity with a catalyst’s conformational equilibrium, as a theoretical basis for the evaluation, design, and prediction of chiral ligand, is described for the addition of diethylzinc to benzaldehyde, and more importantly, a quantitative relationship between the conformations and the enantioselectivity is derived from this catalytic asymmetric kinetic system, which interprets that the observed enantioselectivity is not a weighted average of the enantioselectivity of the individual conformers.