Abstract: It is described the study of hardenability of 86Cr₃ steel by useing Gleeble-1500 thermal simulator. This study has made a contrast test between jominy test and thermal simulate test. The result showed that the method of measuring the hardenability of a high hardenability steel by useing Gleeble-1500 thermal simulator is clearer and more useful than that by jominy test. The cost and test period are low and short respectively. So it can be used as new method for study of hardenability of high hardenability steel.