Abstract: Some necessary data gathered from 5 steel samples treated by different alloys was analyzed through a series experiments of Mg-Ca-based desulphurizers. The results show that Mg-Ca-based alloys have the capacity of deep desulphurization. Mg-Ca-based desulphurizers can overcome the defects of boiling away easily of pure Mg or pure Ca, and enhance every elements' capacities in deoxidation or desulphurization.