The dexanthation of sodium cellulose xanthate has been studied for a viscose prepared from sulphite and kraft pulps. The ripening of viscose was carried out in the presence of an ion-exchange resin which eliminates the rexanthation of cellulose molecule. The decomposition rate of cellulose xanthate at carbon position 2, 3 and 6 were determined. The gamma number at C-2,C-3 decreases continuously during the ripening of viscose, whereas gamma number at C-6 increases initially and passes through a maximum. The viscose prepared from a sulphite pulp showed higher dexanthation rate than that of kraft pulp.