Abstract: The mechanism of sulfur conversion on different acidic zeolites were investigated with aromatic， olefin and thiophene as model compounds at 300℃， and 2.0 h－1 LHSV. The results showed that catalysts with different acidity type possessed different activities of sulfur conversion. The catalysts with both Broensted and Lewis acids showed better conversion of thiophene. Alkyl thiophene with longer and more chains tended to adsorb on the active sites. Acidity type influenced the components of model compounds. Catalysts with both Broensted and Lewis acids decreased the aromatic and olefin greatly，while catalysts with only Lewis acids converted aromatic greatly，but had little effect on olefin.