With the incorporation of hydrogen peroxide($H_2O_2$) and NaLS as an initiator and emulsifier, acrylic acid monomer was graft copolymerized with sodium alginate prepared from alginic acid, and then the grafted copolymer was confirmed through IR spectrometer. When the amounts of acrylic acid increased the grafting also showed increasing trend. While the contents of hydrogen peroxide was varied in the aqueous sodium alginate solution, the grafting efficiency decreased gradually as the amounts of initiator increased.