A welding system performs communication accurately without provision of a control line between a welding power supply device and a wire feeding device. The welding system includes a welding power supply device, a wire feeding device, a welding torch, and power cables for supplying welding power from the welding power supply device to the welding torch. The system also includes power transfer lines for supplying power for driving a feeding motor disposed in the wire feeding device, so that the welding power supply device and the wire feeding device perform communication via the power transfer lines. The power transfer lines have less superimposed noise compared to the power cables. Accordingly, communication can be performed more accurately than in the case of performing communication via the power cables.