The reactions of cellulose nitrate with imidazole and 2-methylimidazole are researched. As a result of reactions solid polymeric and monomeric soluble products are obtained. The elemental composition of this substances is determined and empirical formula of the elementary unit is calculated. On the basis of quantum-chemical calculations perfomed using the Gaussian 09 and physic chemical methods of analysis structure of the products have been established and the most probable directions of the reaction are offered.