Abstract: Electromagnetic stirring process for the round billet mould (450 mm in diameter) in No. 1 Steelmaking Plant of Maanshan Steel in China was analyzed by using mathematical simulation. Orderliness was found out in order to optimize flow path in the round billet mould and make certain reasonable casting parameters. Computational results of electromagnetic stirring process indicated that the magnetic field intensity increases with the stirring frequency decreased and the stirring electric current increased. The electric current intensity does not change magnetic field distribution. The characteristic of magnetic field along the mould vertical direction is strong in the middle and weak at the end of the mould. The optimized processing parameters are the stirring electric current of 350 A and the stirring frequency of 2 Hz.