Separation of the barely studied mixture of acetophenone and 1-phenylethanol, a typical by-product obtained by oil refinery plant, based on the preferential affinity of beta-cyclodextrin (abbreviated as beta-CD) for acetophenone is focused. To demonstrate the potential application of beta-CD for separation of acetophenone from 1-phenylethanol, the noncovalent interactions of beta-CD with acetophenone and 1-phenylethanol were compared from thermodynamic and conformational points of view. For the purpose of separation, a multicomponent coprecipitation technique has been established based on the selective noncovalent binding property of beta-CD, which has been proved rigorously. Under the optimized conditions, the acetophenone/1-phenylethanol equimolar binary mixture can be separated with a separation factor >37. For the petrochemical by-product, which contains 74.93 wt % of acetophenone, 17.79 wt % of 1-phenylethanol, and other minor compounds, expanding the separation scale, content of acetophenone in complex can get 99.2%, and the separation efficiency of beta-CD kept stable after recycling twice. (C) 2014 American Institute of Chemical Engineers