In this paper, a physical modeling to investigate the effects of dam on the fluid flow characteristics in a four-strand tundish of BCC (Bloom Continuous Caster) were described. The 1:3 reduced scale model tundish in the Steel and Aluminum R&D Department, CSC was used in this study to provide guidance for the design of dam size and location in the tundish. Flow patterns can be visualized after injecting dye as a pulse tracer. KCl was selected to be pulse tracer injected to obtain the RTD (Residence Time Distribution) curve. The approach adopted in the present study was to use the concept of a mixed model to analyze the RTD curve. The desired information of plug flow volume fraction, dead volume fraction, mixed volume fraction, minimum residence time, mean residence time and inverse Peclet number were obtained from the RTD curve to assess the flow characteristics in the tundish. An experiment design of the Taguchi method using an L9 orthogonal array to find the optimum dam design for four-strand tundish has been established.