The quantum chemical method is employed to study the enantioselective reduction of imine with borane catalyzed by chiral oxazaborolidine. All the structures are optimized completely at the B3LYP/6-31G(d) level. The catalysis property of oxazaborolidine is notable. The reduction goes mainly through the formations of the catalyst-borane adduct, the catalyst-borane-imine ad-duct, and the catalyst-amidoborane adduct and the dissociation of the catalyst-amidoborane ad-duct with the regeneration of the catalyst. The controlling step for the reduction is the dissociation of the catalyst-amidoborane adduct. The main reduced product predicted theoretically is (R )-sec- ondary amine, which is in agreement with the experiment. The quantum chemical method is employed to study the enantioselective reduction of imine with borane catalyzed by chiral oxazaborolidine. All the structures are optimized completely at the B3LYP / 6-31G (d) level. The catalysis property of oxazaborolidine is not available. through the formations of the catalyst-borane adduct, the catalyst-borane-imine ad-duct, and the catalyst-amidoborane adduct and the dissociation of the catalyst-amidoborane ad-duct with the regeneration of the catalyst. The controlling step for the reduction is the dissociation of the catalyst-amidoborane adduct. The main reduced product solutions theoretically is (R) -sec-ondary amine, which is in agreement with the experiment.