In order to investigate the effects of preparation methods of specimens on liquefaction properties of two kinds of sandy soils, a series of cyclic undrained triaxial tests was performed on the sandy soils under the different conditions in grain size distribution and compaction thickness. Test specimens were prepared by the moist-tamping method. Test results showed that liquefaction resistances were influenced by the thickness of the compaction layer, and its tendency was changed depending on the grain size distribution and compaction degree, Dc. In addition, it was found that a difference in initial moisture content has an influence on deformation properties during cyclic loadings.