Paper-making grade CMC Sodium carboxymethyl cellulose has excellent adhesion, thickening, emulsion, suspension, flocculation, film, protective colloid, retain water, chemical stability and excellent properties such as pulp fiber affinity, introduction of the hydrophilic carboxymethyl groups in its molecular structure, make the swelling of cellulose have greatly increased, easy to pulp fiber and filler particle affinity, enhance toughness and strength of paper; Can promote the pulp and filler with negative charge and mutually exclusive, so that the fiber and filler evenly dispersed in the pulp, improve the paper uniformity; Paper-making grade CMC Can be used in surface sizing agent to improve the strength and smoothness of paper; It can disperse pigment well and improve the effect of printing and dyeing. It can improve the water retention effect by controlling and adjusting the rheology of coating. It can show better whitening and hue improvement effect than starch, polyethylene glycol and other fluorescent brightening agent carrier, it is a multi-functional paper making assistant.