The　effects　of　austenitizing　temperature,　tempering　temperature　on　microstructure　and　hardness　of　high　vandium　high　speed　steel　were　investigated.　The　results　show　that　the　hardness　increases　as　the　austenitizing　temperature　increases　under　air　coolonjg　when　it　is　lower　than　1050　°C;　while　the　hardness　decreases　as　the　austenitizing　temperature　increases　when　it　exceeds　1050　°C.　When　tempering　temperature　is　lower　400　°C,　the　hardness　of　high　vanadium　high　speed　steel　has　little　change,　while　it　will　increase　along　with　the　increase　of　tempering　temperature　when　the　temperature　exceeds　500　°C　and　the　highest　hardness　is　obtained　at　530　°C,　and　the　hardness　will　decrease　as　the　tempering　temperature　continues　to　increase.