A　severe　fracture　failure　occurred　on　a　blast　blower　impeller　which　had　merely　been　in　service　for　15　days.　Overall　evaluation　of　the　combination　property　and　failure　analysis　to　the　impeller　were　obtained　based　on　metal　magnetic　memory　test,　which　is　an　up-to-date　technique　that　could　diagnose　premature　defects,　and　other　methods　from　both　macromechanics　and　microstructure　aspects:　I)Both　the　strength　and　plasticity　of　the　material　were　low,　and　the　tenacity　of　a　sort　was　dispersive,　2)Coarse　grain　was　examined　through　the　process　of　microscopic　examination,　and　the　brittle　fracture　feature　was　observed　in　the　fractographs;　3)Three　regions　of　stress　concentration　on　the　fracture　surface　are　indicated　by　the　magnetic　intensity　analysis　and　it　shows　the　inevitability　of　the　failure;　4)The　reason　of　the　fracture　was　confirmed　to　be　the　fast　fatigue　fracture　caused　by　defective　forging　and　the　following　heat　treatment.　The　correlation　of　failure　reasons　of　three　accidents　of　impeller　fracture　within　5　years　were　also　discussed　in　this　paper.