A series of triethylammonium-based chlorogallate（Ⅲ） ionic liquids with varied Lewis acidity was synthesized, characterized, and firstly applied to isobutane alkylation. The [Et3NHC1]-GaCl3 with XGaCl3 =0.65 displayed a potential catalytic activity for the alkylation. The addition of copper halide into the chlorogallate（Ⅲ） ionic liquids dramatically enhanced the alkylation reac- tion. Up to 70.1% Cs selectivity and 91.3 RON were achieved with the [Et3NHC1]-GaC13-CuC1 （XGaCl3 = 0.65, CuCI = 5% tool） under 0.5 MPa, 900 r/min, 15 min, 288 K using the industrial C4 cut （isobutane/butene = 10）. These results indicate that the chlorogallate（Ⅲ） system may be used as a promising catalyst for the C4 alkylation.
