The present invention discloses a current regulator circuit capable of reducing current ripple and a method of reducing current ripple. A power supply circuit generates a load current which originally has a current ripple. The load current is supplied to a load circuit. The current regulator circuit includes a regulator switch coupled to the load circuit, a current sense circuit for sensing the load current, and a control circuit. The control circuit controls the regulator switch to regulate a peak of a current sense signal minus an average of the current sense signal to a non-negative first predetermined value, or regulate the peak minus a valley of the current sense signal to a non-negative second predetermined value.