Deoxidation and non-metallic inclusion controlling experiments of 3 heats with different deoxidation process at a steel bearing 1.5% Aluminum were done in a MoSi₂ furnace with Φ70mm×100mm MgO at 1873K. The test heats get the high deoxidation ratio and the low terminal total oxygen content. The maximum deoxidation ratio is 84.1% and the minimum total oxygen content is 0.0007% in the process of Mn+Nb-Ti-Al-Ca. After the Aluminum were put into the molten steel, the diameter and number of the inclusions become bigger. In the terminal steels, most of the inclusions are compound bearing Al₂O₃, their outside are coated by CaS or MnS. The diameter of them are 0～3μm.