Newly　developed　polyvinyl　pyrrolidone　(PVP)-based　quenchants　have　more　oil-like　cooling　characteristics　and　thus　can　replace　oil　for　quenching　high　alloy　steel　with　complicated　sections.　The　factors　influencing　the　cooling　rate　are　studied　in　this　paper　using　the　method　of　orthogonal　regression.　The　regression　equations　show　that　concentration,　bath　temperature,　and　agitation　are　highly　significant　factors　in　the　maximum　cooling　rate.　For　the　cooling　rate　at　300degreesC,　concentration　is　critical,　temperature　is　related,　but　agitation　is　not　related.　Based　on　the　regression　equation,　suggestions　regarding　the　better　control　of　cooling　rate　in　practice　are　given.