Alkylation of anthracene with 2-chloropropane to 2-isopropylanthracene catalyzed by various Lewis acidic ionic liquids (ILs), such as [Emim]Cl-AlCl3, [Emim]Cl-FeCl3, [Emim]Cl-ZnCl2, [Bmim]Cl-AlCl3, and [Omim]Cl-AlCl3 ([Emim]+=1-ethyl-3-methylimidazolium cation, [Bmim]+=1-butyl-3-methylimidazolium cation, [Omim]+=1-octyl-3-methylimidazolium cation,), was investigated. [Emim]C1-A1C13 ionic liquid was found to be the most active catalyst in the alkylation. The yield of 2-isopropylanthracene was up to 74.5% and the selectivity of 2-isopropylanthracene was up to 82.9%. The [Emim]C1-A1C13 ionic liquid catalyst showed good catalytic activity after running for 6 times. Ease of product separation and the recycling performance of the ionic liquid catalyst is expected to contribute to the development of clean and environmentally friendly strategy for the synthesis of 2-isopropylanthracene.