Ion exchange of LiNO3 molten salt into Na2O–ZrO2–P2O5–SiO2 glass ceramics was successfully performed in order to obtain Li-exchanged Na+ superionic conductor (NASICON)-type glass ceramics. This procedure was carried out to stabilize the Li-ion-exchanged NASICON-type crystals in a system composed of Li2O–ZrO2–P2O5–SiO2. The total conductivity of the prepared system increased as the X value in the 20Li2O–XZrO2–15P2O5–(65-X)SiO2 system increased, reaching a maximum conductivity value of 3.0 (±2.0)×10−4S/cm (X=30). The conductivity was affected by the existence of the Li3PO4 phase, which was present in the Li-exchanged glass ceramics.