Amorphous　melt-spun　ribbons　of　Pr4.2Tb0.3Fe78B17.5　alloy　were　consolidated　into　bulk　nanocomposite　magnets　by　Spark　Plasma　Sintering　method.　Effect　of　sintering　conditions　on　the　density,　microstructure　and　magnetic　properties　were　studied.　Higher　sintering　temperature　improved　the　densification　of　the　magnets,　while　deteriorated　their　magnetic　properties　simultaneously　due　to　the　excess　crystal　grain　growth.　Magnet　possessed　a　B-r　of　1.04　T　and　a　H-j(c)　of　220　kA/m　under　the　optimal　sintering　condition,　and　its　microstructure　contained　satisfied　grains　with　an　average　size　of　about　20　nm.