The cobaloxime complex crystals with the beta -cyanoethyl group as an axial group and the biphenylboron group substituted to the equatorial ligand were prepared. When the crystals were irradiated with a xenon lamp, the beta -cyanoethyl groups were changed to the alpha -cyanoethyl group with retention of the single crystal forms. The produced alpha -cyanoethyl groups were not racemic but chiral depending on the asymmetry around the beta -cyanoethyl groups in the original crystals. It was made clear from the structure analyses before and after the reaction that the steric repulsion of the biphenylboron group with the produced alpha -cyanoethyl group is responsible to the generation of chirality.