It was amazed that the catalytic system was combined  -cyclodextrin (  -CD, 10 mol%) with (4R)-4-phenyl-oxazolidin-2-one ( 2mol% ) in phosphate buffer, which can catalyzed aldol reactions. The optimal catalytic condition of (4R)-4-phenyl-oxazolidin-2-one for the aldol reaction was investigated by performing a model reaction using stoichiometric of various aryl aldehydes and cyclohexanone respectively in three kinds of phosphate buffer (pH 3.8, 7.0, 10.5). To compare the catalytic effect of (4R)-4-phenyl-oxazolidin-2-one that three comparing experiments were carried out at the optimal condition (pH 10.5 and p-nitrobenzaldehyde). Although the catalytic effect is lower than L-proline at same condition (reaction time, yield and ee), it has been expended the application of (4R)-4-phenyl-oxazolidin-2-one only as chiral auxiliary in asymmetric synthesis.