An improved process for the preparation of a cellulose solution for spinning of fibers, filaments or films therefrom comprising the steps of: a) activating cellulose in a mixture containing said cellulose, tertiary amine oxide solvent and water for a period sufficient to allow a swelling of the cellulose by introduction therein of water present in said mixtures, the temperature of said activation step and concentration of solvent being such that the solvent is not converted into its monohydrate state during the step of activation; b) the cellulose mixture being subjected to the steps of dissolution of cellulose in the solvent by heating for removal of water so as to convert the solvent into at least its monohydrate form so as to cause a dissolution.