The acylation of isobutylbenzene by using catalytic amount of Bi(OTf) 3 has been investigated as function of reaction time, reaction temperature, catalyst dosage and acetyl chloride. It was found that the catalytic activity of Bi(OTf) 3 could be greatly enhanced in the presence of LiClO 4 in nitromethane. Under the optimum condition: Bi(OTf) 3 20%, 4 mol/L LiClO 4-CH 3NO 2, 8 h and 100 ℃, the yield of 4-isobutylacetophenone was up to 90%.