LDPE films were modified via direct gamma -radiation grafting of acrylamide (AAm) from its 30% aqueous solution. Equilibrium swelling of the grafted samples in water, and a water/PAAm molar ratio in the swelled films were determined as a function of PAAm content. Contact angles formed by sessile drops of water or diiodomethane on the starting and modified LDPE were measured with following calculation of a surface energy in these samples. A gradual filling of LDPE surface with PAAm as well as changes in hydrophilic-hydrophobic properties of the composition during the grafting process was discussed. It has been found an essential increase in surface energy of the modified LDPE up to similar to 15% of the grafted PAAm. content with a further stabilization of the energy value.