Abstract: Imidazolium perrhenate was applied as the catalyst to promote the degradation of microcrystalline cellulose (MCC) with the solvent of ionic liquid 1-allyl-3-methyl imidazolium chloride (AmimCl). The effects of reaction temperature, reaction time, reactant concentration, the amount and structure of catalyst on the degradation of cellulose were studied in details. When using 5% of mim-(CH₂)₃SO₃HReO₄, 70μL of water, 0.1g cellulose and 2.0g AmimCl under microwave irradiation for 30min at 160℃, 89.6% of total reducing sugar (TRS) and 46.7% of glucose yield can be obtained. The degradation mechanism of cellulose catalyzed by imidazolium perrhenate was also studied.The hydrogen bonding between hydroxyl groups of cellulose and ReO₄ anion and aromatic ring cation of catalyst is assumed to be the key step for depolymerization of cellulose.