The influence of roll bending on center segregation in continuously cast slabs was studied by conducting the test in which roll bending was controlled during casting. The behavior of roll bending and center segregation in sequential casting were also investigated. As a result, it was clarified that (1) variations in center segregation in the casting direction are attributable to roll bending and center segregation deteriorates with increasing roll bending, (2) the amount of roll bending increases up to 1.7 mm during casting, as a result of which variations in center segregation in the casting direction are increased and segregation deteriorates with increasing number of cast heats in sequential casting, and (3) the use of divided rolls in the final stae of solidification is effective in decreasing roll bending and keeping center segregation at lower level. Of all mechanical factors, roll bending was estimated to be the largest factor for deterioration of center segregation in the case of casting employing one-piece rolls of conventional type.