The benzene acylation was carried out with acetic anhydride as an acylating agent in vapor phase over HZSM-5, Si/Al = 30 and 280, HY and Ce-, V-modified HZSM-5(30) zeolite catalysts at atmospheric pressure. The yield of acylated product acetophenone was found to be 82.1 wt% with 95.0% selectivity at 86.4 wt% conversion of acetic anhydride over Ce-modified HZSM-5(30) where Bronsted acidic sites are active for this reaction.