In this article, the sorption of vapors of various alcohols by cellulose samples has been studied. Isotherms of vapors sorption of all studied alcohols have a sigmoid shape combining multilayer surface adsorption and absorption with capillary condensation at the final stage. To separate sorption from capillary condensation, the thermodynamic equation was used describing only the sorption process. It was found that sorption of methanol vapor was performed via absorption of alcohol molecules by accessible clusters of amorphous domains of cellulose. In contrast to methanol, the sorption of vapors of higher alcohols such as propanol and butanol by cellulose is carried out by the mechanism of multilayer surface adsorption. Sorption of ethanol vaper by cellulose combined multilayer surface adsorption and very limited absorption by accessible clusters of amorphous domains of cellulose.