In　this　paper,　a　novel　fabrication　process　of　the　nanocrystalline　Sm3Co　alloys　and　their　fundamental　properties　were　studied.　The　polycrystalline　Sm3Co　bulk　material　was　prepared　by　the　vacuum　melting　method.　By　using　the　polycrystalline　Sm3Co　bulk　metal,　the　nanocrystalline　Sm3Co　alloys　with　an　average　grain　size　of　about　8　nm　was　prepared　by　combined　ball　milling　and　spark　plasma　sintering.　The　crystal　structure　model　was　constructed　and　the　magnetic　and　mechanical　properties　of　the　polycrystalline　and　nanocrystalline　Sm3Co　alloys　were　characterized　and　compared　with　each　other　in　detail.　Results　show　that　the　nanocrystalline　alloys　exhibit　magnetic　properties　and　high　mechanical　properties.　Microhardness　and　elastic　modulus　of　the　nanocrystalline　Sm3Co　alloys　are　4.87　GPa　and　63.7　GPa,　respectively,　which　are　increased　by　8.7%　and　13.3%　as　compared　with　the　polycrystalline　alloys.