La　nano-powders　with　average　size　of　particles　being　20　nm　were　obtained　through　hydrogen　arc　plasma　method　using　La　as　raw　material.　Then　Sub-micron　LaB6　bulk　were　successfully　prepared　by　utilizing　spark　plasma　sintering　(SPS)　technology　with　La　and　B　nano-powders　as　starting　materials.　The　effects　of　sintering　parameters　on　microstructure　and　properties　were　systematically　studied　and　the　optimal　parameters　were　obtained.　Relative　density　and　Vickers　hardness　of　the　sintered　LaB6　sample　reached　99.3%　and　14.1　GPa,　respectively.　Composition　and　Micro-structure　of　the　samples　were　analyzed　by　means　of　XRD,　SEM　and　TEM.　The　results　showed　that　LaB6　samples　with　fine　grains,　uniform　microstructure　and　high　density　could　be　prepared　by　utilizing　SPS,　the　average　grain　size　of　the　samples　was　150　nm.　The　experiments　showed　that　SPS　process　could　accelerate　consolidation　of　the　synthesis　process　to　achieve　rapid　sintering.