Abstract: A numerical method was used to analyze and calculate important microstructural parameters in dendrite growth under different continuous casting conditions.The dendrite tip radius,dendrite growth velocity,and dendrite arm spacing were investigated and the effects of casting speed on these parameters were studied in combination with continuous casting properties of medium carbon steel.C,Si,Mn,P and S microsegregation in the steel was discussed.The validation of this model shows good and reasonable agreements with previous models.