The long-range structure of konjac glucomannan(KGM)is studied by using laser light scatter(LLS), gel permeation chromatography(GPC)and method of viscosidity. The weight-average molecular weight(Mw), root-mean-square ratio of gyration[(S2)1/2], second viral coefficient(A2)and multi-dispersion coefficient(Mw/Mn)are 1.04×106, 105. 0±0. 9 nm,(-1. 59±0.28)×10-3 mol ml g-2 and 1.015±0.003, respectively. Mark-Houwink equation is established as [η] = 5. 96×10-2Mw0.73 and the molecular chain parameters are as follows: ML=982. 82 nm-1, Lp = 27. 93 nm, d = 0. 74 nm, h = 0. 26 nm, L = l 054.11 nm. Further more molecular chain morphology of KGM is studied by using atom force microscope(AFM)and transmission electronic microscope(TEM), and the result shows that the KGM molecular is an extending semi-flexible linear chain without branch. Therefore, the image of molecular chain morphology confirms the deduction drawn by Mark-Houwink equation and molecular chain parameters. The long-range structure of konjac glucomannan (KGM) is studied by using laser light scatter (LLS), gel permeation chromatography (GPC) and method of viscosidity. The weight- average molecular weight (Mw), root- mean- square ratio of gyration [(S2) 1/2], second viral coefficient (A2) and multi-dispersion coefficient (Mw / Mn) were 1.04 × 106, 105.0 ± 0.9 nm, (-1.59 ± 0.28) × 10 Mark-Houwink equation is established as [η] = 5.96 × 10 -2 M w 0.73 and the molecular chain parameters are as follows: ML = 982. 82 nm- 1, Lp = 27. 93 nm, d = 0.74 nm, h = 0.26 nm, L = l 054.11 nm. Further molecular chain morphology of KGM is studied by using atom force microscope (AFM) and transmission electronic microscope (TEM), and the result shows that the KGM molecular is an extending semi-flexible linear chain without branch. Thus, the image of the molecular chain system confirms the deduction drawn by Mark-Houwink equation and molecular chain parameters.