Abstract: Crude konjac powder and acrylic acid were grafted via ⁶⁰Co γ ray irradiation and the factors including reactant weight, style and temperature of drying were discussed which affected the water absorption of copolymer. The copolymer structure was characterized by fourier transform infrared spectroscopy (FT-IR) and scanning electron microscopy (SEM). The results show that the optimum feed ratio is crude konjac powder∶aerylic acid∶NaOH (9.5 mol/L)∶water=3 g∶21 mL∶12.9 mL∶131 mL. The optimum gel drying temperature is 50 ℃. SEM shows that the copolymer has formed dense network structure which is the base of water absorption. FT-IR analysis shows that the crude konjac powder includes starch and it grafts with acrylic acid by irradiation when KGM grafting acrylic acid synchronously.