To provide a CMC-Na exhibiting high soft plastic performances by a high yield value.

The carboxymethyl cellulose sodium salt comprises 60-80 wt.% of a carboxymethyl cellulose sodium salt having an etherification degree of 0.2-0.5 and a 1% aqueous solution viscosity of 10-100 mPa s, 5-15 wt.% of a carboxymethyl cellulose sodium salt having an etherification degree of 0.6-0.7 and a 1% aqueous solution viscosity of 1,000-15,000 mPa s and 15-25 wt.% of a carboxymethyl cellulose sodium salt having an etherification degree of 0.8-1.5 and a 1% aqueous solution viscosity of 100-5,000 mPa s, the total amount being 100 wt.%.