This disclosure provides a method and apparatus for reducing an inrush current inflowing from an external power source during an initial transient state. The method may include generating a first signal based on a level of internal voltage. The first signal may linearly increase or decrease, wherein the slope of the first signal may be fixed. The method may further include comparing the first signal with the reference voltage, and controlling an overcurrent prevention function based on the comparison results. An inrush current reducing device may include a reference voltage generating unit configured to compare a first signal and the reference voltage to control an overcurrent sensing gain, a gain unit configured to compare a first signal and the reference voltage to control an overcurrent sensing gain, and an overcurrent prevention signal generating unit configured to control an overcurrent prevention function based on the comparison results.