Electrical conductivity of xNa(2)O-(70 - x)Nb2O5-30P(2)O(5) glass was examined. The electrical conductivity of the glasses increases monotonously with increasing Na2O content, and the glass of 60Na(2)O-10Nb(2)O(5)30P(2)O(5) shows the value of a = 5.6 x 10(-8) Scm(-1) at room temperature and the activation energy (Ea) of 0.54 eV for Na+ ion mobility from 25 degrees C to 200 degrees C. We also examined the fabrication of glass-ceramic composites, which is consisted from Na3Zr2Si2PO12 and 60Li(2)O-10Nb(2)O(5)-30P(2)O(5) glass. It found that the mixture of 90 wt.% NaNa3Zr2Si2PO12-10 wt.% 60Na(2)O-10Nb(2)O(5)-30P(2)O(5) glass calcined at 900 degrees C for 10 min, gives a = 1.2 x 10(-4) Scm(-1) at room temperature. Na2O-10Nb(2)O(5)-30P(2)O(5) glass is suitable filler material for solid electrolyte in sodium ion batteries. (C) 2014 Elsevier B.V. All rights reserved.