Abstract: The application of mold electromagnetic stirring in continuous casting of middle billet in the Steel Work of Sanming Iron & Steel in Fujian Province was introduced. The optimization of the operation pa-rameters of M-EMS has achieved good metallurgical results, such as decreasing the carbon segregation and pre-venting the central porosity. Those measurements are very useful in improving the quality of products. It is pro-posed that final electromagnetic stirring should be used in the end of liquid core.