A mathematical model on the electromagnetic continuous casting magnesium alloy billets was established to predict the temperature distribution in the billet and dummy block using VC++6.0 and finite differential method（FDM）. Induction heating distributions at horizontal and vertical directions along mould at varied conditions were presented by measuring induction heating and its distribution in electromagnetic continuous casting billets based on temperature-increment method

and induction heating power was calculated

which was considered into the mathematical model for calculating temperature field. Boundary conditions of primary、secondary cooling zone and interfacial cooling between billet and dummy block were determined. The simulated results are well in agreement with the experimental ones

showing the availability of the model. Effects of different parameters on distribution of temperature field in billets were investigated to optimize the processing parameters.