A series of acidic ionic liquids such as [Bmim]HSO4, [Bmim]SbF6, Bmim]PF6, [BSmim]HSO4, [BSmim]CF3SO3, [BSN222]H2PW12O40 and [Ph3PSO3H]HSO4 were synthesized following two-step method to substitute concentrated sulfuric acid as catalyst for esterification of butene. The synthesized ionic liquids and the blending with Lewis salts were used as catalysts for the esterification of butene with acetic acid at 90℃ for 4 h, under the volume ratio of the mixture of butane & butene to acetic acid of 18:5, and the molar ratio of acetic acid to catalyst of 2. As [Ph3PSO3H]HSO4 was catalyst for the esterification of butene, the conversion rate of butene reached 88.8%, selectivity and yield of butyl acetate reached 100% and 88.8%, respectively, versus that values of sulfuric acid as catalyst of 73.5%, 77.7% and 57.1% under the same conditions. After 8 times re-use of [Ph3PSO3H]HSO4 as catalyst for the esterification of butene, the conversion rate of total butene keeps more than 88.4%, selectivity of butyl acetate more than 97.4%.