Moulding material and spinning material respectively containing cellulose, an aqueous tertiary amine-oxide, a non-solvent and a stabiliser, characterised in that, one or more stabilisers are provided which altogether have a basic and antioxidant action with the proviso that the basic stabiliser is not phosphate. The moulding material and spinning material respectively according to the invention are thermally stabilised against a runaway of the decomposition reaction. The degradation of the cellulose and of the amine-oxide is also largely prevented.