Abstract: Characteristics of liquid field in tundish with the straight and curved weir and dam in common use and the new optimized straight and curved weir and dam with guiding flow tube device have been studied by using 1: 3 water model and numerical simulation. Results showed that average residence time, response time and peak time of liquid steel at nozzle increased by using optimized device in tundish, and difference of maximum residence time of liquid steel between each nozzle decreased in some extent which obviously improved metallurgy effect in tundish.