In　this　document,　the　electrolytic　in-process　dressing　(ELID)　grinding　technique　is　used　for　ultra-precision　processing　experimental　research　on　the　carbonized　cold-rolled　steel　(HRC60&　80).A　surface　roughness　of　Ra6&8nm　was　obtained　after　ELID　precision　grinding.　The　results　proved　that　adopting　micro　grain　size　(W1.5&W36)　and　high　hardness　cast　iron　based　diamond　grinding　wheel,　increasing　the　wheel　peripheral　velocity　(18&20m/s)　and　reducing　grinding　depth　can　effectively　improve　surface　quality　and　bring　the　surface　roughness　down.　The　wheel　peripheral　velocity,　grinding　depth　as　well　as　grinding　fluid　are　the　main　factors　during　ultra-precision　grinding.　©　(2012)　Trans　Tech　Publications,　Switzerland.