A 1/10 scale water model experiment was performed to measure the residence time distributions(RTD) of the 300 ton ladle of a RH process. The effects of distance of the snorkels(center to center distance : 170㎜, 210㎜, 250㎜, 290㎜, 330㎜,) and the flow rate(circulation rate : 13.20 L/min, 16.20 L/min, 19.47 L/min) on RTD were investigated. The RTD of the ladle of the RH process differs from that of plug flow or completely mixed reactor. As the distance of the snorkels becomes shorter, the RTD of the ladle approaches that of the completely mixed reactor. And the distance of the snorkels becomes longer, the RTD of the ladle approaches that of the plug reactor. The shapes of the normalized RTDs are not changed by the increase of the flow rates.