The effect of dispersed second phase particles of γ-Al2O3 on the ionic conduction of β-Li2SO4, has been studied. The electrical conductivity of β-Li2SO4 (γ-Al2O3) increases remarkably with the addition of γ-Al2O3. The maximum increment appears at about 50 mol%γ-Al2O3. The conductivity of β-Li2SO4 (50mol% γ-Al2O3) is four orders of magnitude higher than that of pure β-Li2SO4 at 253℃. On the other hand, the conductivity in α-Li2SO4 containing γ-Al2O3 decreases. The conductivity of β-Li2SO4 (γ-Al2O3) prepared in the condition of 70-80% relative humidity increases monotonically with γ-Al2O3 content. The additional small peaks of 7Li NMR absorption spectral in these specimens were found to be more obviously with the increasing of γ-A12O3 content. The obsorption water layers on surfaces of γ-A12O3 particles are responsible for this phenomina. It is also found that quenching of the sintered β-Li2SO4 (30mol%γ-A12O3) pellet has evident effect on conductivity. The conductivity of quenched specimen is two orders of magnitude higher than that of the unquenched.