The ultrasonic velocity and attenuation coefficient have been measured at the frequency 4 MHz and at room temperature using the pulse echo technique. The effect of gamma-radiation (1-10 Gy) on the ultrasonic attenuation, the internal friction and elastic properties inside the modified sodium borate glasses was studied. The used modification oxides are CaO, ZnO, MgO, BaO, and CdO. The results indicate the possibility for using modified sodium borate glasses as gamma-ray dosimeters in the low gamma-radiation doses. (C) 2002 Published by Elsevier Science B.V.