Based on the induced magnetic field of the conducted melt in a rectangular pipe,the 2-dimensional flow field is computed,then the inclusion trajectories are obtained by solving the MHD equations and the particle trajectory equations,respectively.Results show that the induced magnetic field is apt to produce convection in a square pipe,and thus to disturb the inclusion migration.To avoid it,the pipe with rectangular or circular cross section is better to be applied than one with square cross section for the electromagnetic purification.On the other hand,the induced magnetic field has an in built tendency of self limit,which makes it possible to remove inclusion from liquid melts only with currents (DC or AC) rather than with extra magnetic fields.