The　magnetic　properties　of　bulk　nanocrystalline　metal　gadolinium　(Gd)　and　dysprosium　(Dy)　samples　were　studied.　The　magnetization　and　Curie　temperature　TC　of　nanocrystalline　Gd　and　Dy　decreased　usually　as　compared　with　the　polycrystal.　However,　when　the　mean　grain　size　was　10　nm,　the　Curie　temperature　TC　of　nanocrystalline　Dy　increased　to　100　K　instead　and　there　was　an　antiferromagnetic　phase　in　nanocrystalline　Gd.　According　to　the　calculation　based　on　Ruderman-Kittel-Kasuya-Yosida　exchange　interaction,　the　exchange　integral　of　the　grain　boundary　atoms　and　crystalline　surface　atoms　had　its　sign　changed　from　plus　to　minus　or　vice　versa,　and　there　were　three　orderly　phases　in　the　steady　state　with　the　lowest　energy,　ferromagnetic　phase,　antiferromagnetic　phase　and　fan　phase.　For　the　nanocrystals　with　mean　grain　size　of　10　nm,　the　proportion　of　grain　boundary　to　crystalline　surface　atoms　was　high,　and　as　the　result　of　superposition　of　the　three　phases,　and　there　appeared　a　peak　near　the　phase　transition　temperature　for　the　nanocrystalline　Gd.　While　for　the　Dy,　the　magnetization　decreased　gently　with　temperature,　and　showing　a　higher　Curie　temperature　than　in　the　case　of　the　polycrystal.