Cellulose ether is a polymer compound of hydrogen atoms in the anhydrous glucose unit of cellulose is alkyl or substituted alkyl substituted. In the cellulose chains, each glucose unit has three hydroxyl groups can participate in the reaction, if completely replaced, replaced degree index (DS) value of 3, a commercially available product the degree of substitution between 0.4-2.8. When substituted alkylene oxide, are able to form new hydroxyl can further be hydroxyl alkyl substituted, thus forming a chain. The quality definition of each anhydrous glucose olefin oxide compound molar substitution (MS). An important property of commercial cellulose ether mainly depends on the molar mass, chemical structure, the distribution of substituents on cellulose, DS and MS. These properties are usually including solubility, stability in solution viscosity, surface activity, the thermoplastic properties of layer and anti biodegradation, thermal reduction and oxidation. The solution viscosity varies according to the different relative molecular mass.