Abstract: The effect of synthetic method of cellulose carbamate,degree of polymerization of raw materials,synthesis temperature and time,the kind of carrier and its dosage,concentration of urea on nitrogen content of cellulose carbamate were discussed systemically.The results show that the accessibility of the reactant can be increased with carriers added.It is better for the reaction with the degree of polymerization ranging from 320 to 390.The esterification carries on easily when the pH value of the reactive system is over 7.The nitrogen content of the cellulose carbamate increases with the urea concentration increasing and the pre-treatment time protracting,and the optimal synthesis condition is finally determined,that is,the urea concentration is 40%,pre-treatment time is 2 hours and the temperature and time of esterification is(150 ℃) and 3 hours respectively.IR spectrum study indicates the presence of acylamide bond in the cellulose carbamate and X-ray diffraction shows that the type of crystal of the cellulose carbamate is similar with that of cellulose after being activated and the degree of crystallization changes little.