This invention relates to a visual control robot system for arc welding which can conduct easily and efficiently those operations which are associated with a robot controller and a vision sensor system by an operator through a common operation panel. Before the start of welding, a soft key (9a) disposed on the common operation panel (6) for both the robot controller (5) and vision sensor controller (3) is operated so as to set the robot system to a first mode and under this state, the position of a sample welding member is taught to the robot controller. The soft key is then operated to switch an operation mode to a second mode in order to input parameters for vision teaching of storing a camera image at each point on a reference weld line formed on the sample weld member. The position teaching and the vision teaching can be given via the same operation panel and moreover, the operation common to both can be carried out by the same operation. Correction control is effected during the welding work so that an actual weld line is in agreement with the reference weld line in accordance with the result of comparison between an actual camera image representing a welding state and a camera image at the time of vision teaching corresponding to the former.