The influence of gamma and electron radiation on ultrafiltration (UF) membranes has been studied and the changes of their transport properties have been determined at different doses. Samples of UF film (flat) membranes made of different polymeric materials were irradiated, with doses in the range 5 ¸ 200 kGy by immersing in a solution containing 134Cs or using an external ⁶⁰Co source, and 13 MeV electron beam from a linear accelerator. The dependences of the permeate flux and the retention coefficient of dextrines with molecular masses 3·10⁴ ¸ 10⁵ MW on the absorbed dose were investigated.