Hot　cracks　formed　in　pinch　roll　frequently　after　repaired　by　hardfacing　because　the　material　was　chosen　improperly　and　low　purity.　This　happened　even　if　the　hardfacing　technique　and　the　heat　treatment　are　suitable.　After　repairing　the　simulated　pinch　roll　by　hardfacing,　hot　cracks　were　found　and　analyzed　by　optical　microscope　and　scanning　electron　microscope.　The　results　show　that　the　net　cracks　composed　of　main　cracks　and　micro　cracks　near　the　main　cracks.　High　content　of　carbon,　sulfur　and　oxygen　were　detected　in　the　main　cracks.　A　lot　of　low-melting　eutectics　formed　because　of　these　elements　interaction.　Meanwhile　these　impurities　concentrated　on　the　grain　boundary　or　between　dendrites,　so　that　the　solidification　cracks　formed　and　extended.　A　great　number　of　oxides　existed　in　micro　cracks　and　their　segregation　and　aggregation　resulted　in　micro　cracks.