The　as-cast　microstructures　of　high　carbon　high　speed　steels　(HC-HSS)　made　by　sand　casting,　centrifugal　casting　and　electromagnetic　centrifugal　casting,　respectively,　were　studied　by　using　of　optical　microscopy　(OM)　and　D/max2200pc　X-ray　diffraction.　The　results　show　that　the　microstructure　of　as-cast　HC-HSS　is　dominated　by　alloy　carbides　(W(2)C,　VC,　CR(7)C(3)),　martensite　and　austenite.　The　centrifugal　casting　and　electromagnetic　centrifugal　casting　apparently　improve　the　solidification　structure　of　HC-HSS.　With　the　increase　of　magnetic　intensity　(B),　the　volume　fraction　of　austenite　in　the　HC-HSS　solidification　structure　increases　significantly　while　the　eutectic　ledeburite　decreases.　Moreover,　the　secondary　carbides　precipitated　from　the　austenite　are　finer　with　more　homogeneous　distribution　in　the　electromagnetic　centrifugal　castings.　It　has　also　been　found　that　the　lath　of　eutectic　carbide　in　ledeburite　becomes　finer　and　carbide　phase　spacing　in　eutectic　ledeburite　increases　along　with　the　higher　magnetic　field　strength.