The　preparation　and　the　mechanism　study　of　bulk　pure　rare-earth　metals　with　amorphous　and　nanocrystalline　structures,　which　were　produced　by　spark　plasma　sintering　(SPS),　were　carried　out　in　this　paper.　With　different　processing　parameters,　the　amorphous,　two　phases　of　amorphous　and　nanocrystalline,　and　complete　nanocrystalline　microstructures　have　been　obtained.　The　nano-grain　sizes　in　the　bulk　nanocrystalline　materials　are　found　smaller　than　the　original　powder　particles　sizes,　which　may　change　the　conventional　viewpoint　that　the　grains　in　the　sintered　bulk　are　generally　coarser　than　the　raw　powder　particles.　The　technique　developed　in　the　present　work　can　be　extended　to　the　preparation　of　many　other　nano　bulk　metal　materials,　and　thus　enables　the　studies　of　the　nano-size　effects　on　the　physical,　chemical　and　mechanical　properties　of　bulk　nano　materials.