Carboxymethyl starch (CMS) is a kind a modified starch derivatives. Due to the introduction of carboxymethyl group to the starch, it has better viscosity and storage stability, lower gelatinized temperature.

CMS has widely application which includes food, textile, paper, construction industries. CMS is similar with CMC (carboxymethyl cellulose), except to better performance, CMS has more competitive price.