Wet or dry methods are used for starch modification.The modification reagents can be divided into small molecules and macromolecules.Starch modified by dry heating with hydrocolloids is a new type,which includes anion hydrocolloids(xanthan,sodium alginate,carrageenan,sodium carboxymethylcellulose),cationic hydrocolloids(chitosan)and non-ionic hydrocolloids(guar gum).