Ionic conductivity and activation energy of 60 meshpowder, 120 mesh-powder, 200 mesh-powder, tablet pressed with powder and bulk piece of amorphous lithium ionic conductor P2O5-0.7Li2O-0.4LiCl-0.1Al2O3 in the range of 60℃-380℃ were investigated. It is found that decreasing the grain size can enhance ionic conductivity by 4 times and does not affect activation energy, owing to the effect of boundary layer in the same amorphous phase. Research after ionic conductivity measurement and X-ray diffraction of samples heated at 380℃ for 76 hours show that following the grain size becomes smaller, the crystallization process becomes easier. The bulk piece of amorphous sample not only has conductivity two orders higher than that of the tablet sample and lower activation energy, but also is more difficult to crystallize. Hence it possesses higher applicability. Study on DSC, conductivity, XRD and DTA of 60 mesh, 120 mesh, 200 mesh amorphous powder heated at 300℃ for 330 hours and at 350℃ for 612 hours shows that there are more than two amorphous phases and more complex interface effects among different phases in their amorphous phase separation.