A switching regulator which has load transient quick response ability includes at least one power stage circuit and a control circuit. The control circuit includes a pulse width modulation (PWM) signal generation circuit and a quick response (QR) signal generation circuit. The PWM signal generation circuit generates a PWM signal according to an output voltage and a QR signal, to control a power switch of the corresponding power stage circuit, thus converting an input voltage to the output voltage. The QR signal generation circuit includes a differentiator circuit and a comparison circuit. The differentiator circuit performs a differential operation on a voltage sensing signal related to the output voltage, to generate a differential signal. The comparison circuit compares the differential signal with a QR threshold signal, such that when the differential signal exceeds the QR signal, the PWM signal generation circuit performs a QR procedure.