A numerical study for analyzing both fluid flow and mixing behavior in gas-stirred ladles with a submerged lance was performed. At first, the shape and volume of the plumes generated by the submerged nozzle were calculated. Subsequently, the fluid flow driven by these plumes, and the mass transfer in the ladle were calculated by a three dimensional turbulent simulation program. Water model experiments for the velocity measurements were performed to verify the accuracy of the calculation results. It was shown that as the gas flow rate increases, the downward velocity at the ladle wall increases and mixing time decreases. Mixing time is sensitive to the alloy addition position especially at a lower gas flow rate. The result suggested that the alloy should be added at the plume zone close to the center at the melt surface.