Disclosed is a steering system which is capable of ensuring that a wheeled excavator travels straight while being driven on a paved road. The steering system for wheeled construction equipment includes: a hydraulic oil pump; a steering motor connected to the hydraulic oil pump; a steering valve controlling the operation of the steering motor; a steering handle operating the steering motor and the steering valve according to steering manipulation by the driver; and a steering cylinder steered by the manipulation of the steering handle. The steering system further includes an idle mode control unit which converts working mode into a steering mode not having straight line driving recovery performance when working mode, in which working and driving are enabled, is selected, and which converts exclusive driving mode into a steering mode having the straight line driving recovery performance through a signal input when the exclusive driving mode, in which only driving is enabled, is selected.