A system comprising a weld wire used in welding of a weld target , an electrode for melting the weld wire and a welding control device configured to control a position control target including both the weld wire and the electrode for melting the weld wire, characterized in that the weld wire and the electrode are each configured to move relatively to each other in each of a welding direction that is a horizontal longitudinal direction and another horizontal direction that is orthogonal to the welding direction, the welding control device comprising: an actual position determination part configured to determine an actual position of the position control target on the basis of a weld characteristic amount (P) detected from a captured image (V) captured so as to include at least the position control target, the weld characteristic amount (P) including both a wire position (Pw) of the weld wire and an electrode position (Pe) of the electrode; a target position determination part configured to determine a target position being a target of the actual position corresponding to a weld condition (C) for welding the weld target wherein the weld condition includes at least one condition of an electrode current, an electrode voltage, a welding rate, a feeding amount of the weld wire per unit time, or a groove width.; and a position control part configured to execute a position control of the position control target to bring the actual position to the target position. characterized in that the weld wire and the electrode are each configured to move relatively to each other in each of a welding direction that is a horizontal longitudinal direction and another horizontal direction that is orthogonal to the welding direction, the welding control device comprising: an actual position determination part configured to determine an actual position of the position control target on the basis of a weld characteristic amount (P) detected from a captured image (V) captured so as to include at least the position control target, the weld characteristic amount (P) including both a wire position (Pw) of the weld wire and an electrode position (Pe) of the electrode; a target position determination part configured to determine a target position being a target of the actual position corresponding to a weld condition (C) for welding the weld target wherein the weld condition includes at least one condition of an electrode current, an electrode voltage, a welding rate, a feeding amount of the weld wire per unit time, or a groove width.; and a position control part configured to execute a position control of the position control target to bring the actual position to the target position. an actual position determination part configured to determine an actual position of the position control target on the basis of a weld characteristic amount (P) detected from a captured image (V) captured so as to include at least the position control target, the weld characteristic amount (P) including both a wire position (Pw) of the weld wire and an electrode position (Pe) of the electrode; a target position determination part configured to determine a target position being a target of the actual position corresponding to a weld condition (C) for welding the weld target wherein the weld condition includes at least one condition of an electrode current, an electrode voltage, a welding rate, a feeding amount of the weld wire per unit time, or a groove width.; and a position control part configured to execute a position control of the position control target to bring the actual position to the target position. <EOS>