The crystal transformation, degree of crystallinity, and crystallite size of cotton cellulose, treated with liquid ammonia and dried by evaporation, wert investigated. The quantification of crystalline content was carried out by resolution of X-ray scattering intensity distribution on the assumption that all digracted intensities take the form of symmetrical Gauss distribution centering at its Bragg angle. The treatment of liquid ammonia transformed part of cellulose I and II crystals into III crystals, thereby making it a polymorphic structure. The m crystals transformed from I and II crystals, IIIa, and IIIb, had a very close lattice type mutually, but showed a considerable difference on the transformational extent, crystalline disruption behavior, and reversional ability to original crustal.