The impregnable crystalline structure of cellulose has been covalently attacked by cyanuric chloride. XPS results show that a certain content of cyanuric chloride has been introduced into celluloses. CP/ MAS 13C NMR and WAXD demonstrated that the crystal structure of cellulose was destructed. The proportions of crystal planes were changed dramatically by chemical reaction. These destructions and changes enhanced the dilute acid catalyzed hydrolysis of cellulose. Results of this work indicate that hydrolysis of cellulose with higher yield, lower cost, less resource consumption and more eco- friendly aspects can be achieved by chemical modification, which has a significant expectation of potential application