Abstract: The experiment of manganese ore direct alloying for. increasing [Mn] content in steel was carried out. The factors influencing on [Mn] content in steel and manganese yield were studied. The results show that [Mn] content in steel and manganese yield can be increased by decreasing （TFe） of slag,controlling basicity of slag in the range of 2~4 and increasing [C] content and temperature in steel. The reducing ability of SiC for reduction of （MnO） in slag is superior to that of coke. Manganese ore direct alloying technique can indirectly improve desulphurizing ability of slag