In this paper, the relativity on the granularity with different mesh of konjac glucomannan (KGM) and molecular dimension was discussed. Laser particle size analyzer, laser light scattering and digital polarimeter were used to analyze the granularity distribution, molecular characteristics and polarity of KGM. The results showed that the granularity of KGM after gradient refining was gradually decreased and KGM was well dispersed in ethanol(D50=13.11μm).The Mw of KGM was gradually decreased with its granularity decrease and its molecular conformation was from globular to linear structure. The space asymmetry of KGM at 80-100 meshes was minimum and its polarity was maximum. The primary establishment on the relativity offered the references to KGM theoretical research and practical application.