In the 1.1 Mn steel containing boron, effects of the 0.1 V addition and processing condition were studied. In the $550^{circ}C$ interrupted cooling where the main structure is (ferrite + pearlite), the impact toughness decreased as the tensile strength increased by the 0.1 V addition. The $800^{circ}C$ rolling including two step rolling of $800-770^{circ}C$, exhibited better strength-toughness balance, as compared to the $770^{circ}C$ rolling. This seems to be kind of conditioning effect at higher temperature, e.g., more uniform deformation effect. In the accelerated cooling after the $750^{circ}C$ rolling in a dual phase range, the impact toughness was enhanced, despite a large increase in tensile strength. This is believed to be related to the change of main structure from (ferrite + pearlite) to (ferrite + bainite).