An overcurrent protective system includes a current detector which detects a current flowing in an element which is to be protected by the overcurrent protective system, an overcurrent counting unit which selects an overcurrent sensing level corresponding to the element among a plurality of overcurrent sensing levels which are threshold values becoming standards for determining whether the current detected by the current detector is a normal current or an overcurrent and which determines whether the current is the overcurrent or not by comparing the current with the selected overcurrent sensing level, and a controller which decreases an output voltage of a circuit which is to be protected by the overcurrent protective system and includes the element when the current flowing in the element is determined as the overcurrent.