A novel kind of spherical cellulose nanocrystal (SCNC) suspension was prepared by hydrolysis of microcrystalline cellulose with a mixture of sulfuric acid and hydrochloric acid under ultrasonic treatment. The mechanism of SCNC formation and the liquid crystalline properties of their suspensions were investigated. A suspension of spherical particles was usually inclined to form crystallization colloids rather than liquid crystals at high concentration. However, a SCNC suspension with high polydispersity (49%) was observed to form the liquid crystalline phase, and the liquid crystalline textures changed with increasing concentration. This observation offers an approach to the liquid crystal formation of highly polydisperse spherical nanoparticles.