The paper suggests the analysis of the x-ray diffraction trace of viscose rayon by the correlation- crystallinity index method for routine assessment of crystalline order in samples composed of cellulose II, and by the multipeak-resolution method for special analysis of crystallinity and crystallite size in samples composed of either cellulose II only or cellulose II + cellulose IV. Sets of samples of viscose rayon produced under controlled conditions are x-ray characterized, the tensile properties are measured, and the significance of crystallinity on tensile properties is sought.