Based on the reaction mechanism of cellulose sulphation, an improved process for the preparation of sodium cellulose sulphate (NaCS) was developed, in which the reaction solution could be regenerated by adding fuming H2SO4 (oleum) and/or normal H2SO4 and used many times. The NaCS prepared in this process showed the same qualities as that obtained with fresh reaction solution. This regeneration method successfully improved the process of production of NaCS, i.e. the costs of production and corrosive waste were greatly reduced.