Nanocomposites of butadiene-acrylonitrile copolymer (NBR) and cellulose II were obtained from mixtures of nitrile rubber latex and cellulose xanthate by using a co-coagulation system. The influences of low and medium acrylonitrile content in NBR and the cellulose II content, varying from 0 to 30 phr, were investigated by means of rheometric and equilibrium swelling experiments. The cure parameters obtained from the Oscillating Disk Rheometer data were utilized to characterize the structure of cellulose II present in the rubber vulcanizates through Wolff's equation. The swelling experiments were analyzed by using Flory-Rehner theory and Kraus and Cunneen-Russel equations to evaluate the NBR-Cel II interaction. From the results it was possible to conclude that cellulose II promotes a positive influence on cure parameters and crosslinking formation. It was also observed that the high butadiene content in NBR facilitated the interaction rubber-cellulosic component. The dispersion and distribution of cellulose in NBR matrix gave rise to nanomaterials, as observed by transmission electron microscopy.