The pseudo-binary systems Li2SO4-Li2B2O4, Li2SO4-(NH4)2SO4 have been studied by means of DTA and X-ray diffraction techniques. Li2SO4-Li2B2O4 is a eutectic system. The eutectic reaction occures at 720℃ and 75 mol% Li2SO4. In Li2SO4-(NH4)2SO4 system there exists only one compound NH4LiSO4 which has a solid-solid phase transition at 186℃.The ionic conduction in both crystalline, amorphous Li2B2O4 and some samples with different compositions in Li2SO4-(NH4)2SO4 system have been investigated. It was found that below 400℃ the conductivity of amorphous Li2B2O4 is at least more than two orders of magnitude higher than that of crystalline sample and the activation energy of conduction is much smaller. The activation energy of LiNH4SO4 high temperature phase is only 0.12 eV while it's room temperature phase has a value of 0.70 eV. The ionic conductivity of the sample containing Li2SO4 40 mol% (LiNH4SO4 + [NH4]2SO4 two phase mixture) of the high temperature phase is about two orders of magnitude higher than that of pure LiNH4SO4. This suggests that when one kind of ionic crystal is added as a second phase into another ionic crystal, the ionic conductivity ofthe later could be increased remarkbly.