Sodium alginate is used as active dyestuff in printing and dyeing industry that is better than foodstuff amylum and other plasm. The textile that is printed by it has fresh grains, clear line, high coloring capacity, even painting, good penetrability and plasticity. Sodium alginate is the best plasm for modern printing and dyeing, which is wide used for cotton, feather, silk and nylon and other textile; furthermore, it is applicable for discharge printing paste.