In order to recognize the effects of the process parameters on the flow pattern in the ladle during RH degassing process, a numerical approach of k-ε turbulent model and a water model experiment were carried out. It was found that molten steel flows in the ladle have high turbulent characteristics and RH degasser is an excellent mixer. The maximum values of turbulent energy as well as dissipation rate of turbulent energy occur in the vicinity of the snorkel. The computation formula of circulation rate was derived from the results of the water model experimint. Furthermore, it was proved that the energy balance in RH degassing process is the effective means for predicting cir-culation rate.