Abstract: Three kinds of H₃PO₄/[R mim]BF₄ composite were first used to catalyze the synthesis of terpinyl acetate. H₃PO₄/[C₄mim]BF₄ and H₃PO₄/[C₈mim]BF₄ have high catalytic activities. Taking H₃PO₄/[C₄mim]BF₄ as the representative, the effects of dosage of H₃PO₄ catalyst, reaction temperature, molar ratio and reaction time on selectivity of terpinyl acetate were studied. Under the above conditions,mass fraction of unreacted terpineol was only 0.9%,while terpinyl acetate was 86.5% and pinene was 11% in the product. After H₃PO₄ /[C₄ mim]BF₄ was repeatedly used for seven times, the catalytic activity was comparative to the new catalytic system when some H₃PO₄ was supplemented.

Key words: ionic liquids, terpinyl acetate, esterification, turpentine