Abstract: The physical and chemical properties of PEO R 150 water swollen hydrogel films formed by electron beam irradiation are studied and compared with PEO R 150 hydrogel films The experimental results show that the irradiation dose and mass fraction ofthe polymer do not produce a significant effect on the gel fraction, of the PEO R 150 water swollen hydrogel films( P >0.05). The degrees of swelling of the PEO R 150 water swollen hydrogel films decrease as the irradiation dose increase( P <0.01), while they increase as mass fraction of the polymer increase( P <0.01), and both factors have a mutual effect on the degrees of swelling( P <0.01). The hardness of the PEO R 150 water swollen hydrogen films increase slightly as the irradiation dose increase, while it decrease slightly as mass fraction of the polymer increase. Comparing with the PEO R 150 hydrogel films, PEO R 150 water swollen hydrogel films could significantly increase their gel fractions( P <0.05 or P <0.01) and decrease their degrees of swelling( P <0.05 or P <0.01), while their hardness did not increase significantly( P >0.05). The results indicate that the saturant crosslinking density, the lowest degree of swelling of the PEO R 150 water swollen hydrogel films produce an unfavorable effect on their machinery strength.