The high conductivity a-Si:H:Y alloy films prepared by rf sputtering have been obtained. The room temperature d.c. conductivity is about 2×101 Ω-1·cm-1 as Y doping concentration reaches 20 at %. Measurements showed that the alloy films are of n-type. The plots of In a versus 1/T over temperature range investigated can be fitted by two straight lines with a kink occurring at a temperature which is ～70℃, ～75℃ and ～90℃, respectively, for samples deposited at substrate temperature T2 = 260℃, 290℃ and 330℃. Present results may be explained on the assumption that there are two parallel transport paths, one above kink temperature takes place in the conduction band and another below kink temperature in the Y-rela-ted donor impurity band, Moreover, we estimated that the center of the impurity band lies about 0.06-0.07 eV below the conduction band EC.