Na 2 O) 35.7 (MO) 7.2 (SiO 2 ) 57.1 and (Na 2 O) 33.7 (MO) 13.3 (SiO 2 ) 53.4 glass materials that feature alkaline earth metals (M = Mg, Ca, Sr, Ba) were evaluated as Na + conducting materials. Following glass synthesis from the melt under air at 1350 °C, Na environments, conductivity, and water leaching were investigated. 23 Na NMR spectrometry indicated NaO distances decreased in the order M = Mg > Ca > Sr > Ba. The conductivities and activation energies of conduction respectively decreased and increased slightly in the order M = Mg, Ca, Sr, and Ba. Regardless of M, the conductivities and activation energies of conduction of (Na 2 O) 33.7 (MO) 13.3 (SiO 2 ) 53.4 were lower and higher, respectively, than those of (Na 2 O) 35.7 (MO) 7.2 (SiO 2 ) 57.1 . Na leaching into water decreased in the order Ca < Mg < Sr < Ba. For each M, (Na 2 O) 33.7 (MO) 13.3 (SiO 2 ) 53.4 was more resistant to leaching than (Na 2 O) 35.7 (MO) 7.2 (SiO 2 ) 57.1 .