Abstract: To solve the problems such as relatively big dead zones,insufficient flotation of inclusions and high casting remnant in tundishes when producing high quality interstitial-free (IF) steel,a series of optimizing measures were practiced in water modeling experiments. The results show that the fluid flow manifests an obvious up-ward trend using the high dam with two upward holes,the minimum residence time increases by 12.5%,and the dead zone decreases by 36%. In the end of casting,liquid steel can flow out through the holes avoiding a large amount of steel between the dames,the theoretical casting remnant declines from 9 to 4.5 t,and the metal yield increases obviously.