A Light Emitting Diode, LED, lighting system comprising: a main transformer (1300, 3300) configured to transform an input signal to supply the transformed input signal to an LED group (1400, 3400); a voltage detector (1700, 2700) configured to supply a control voltage (Vcontrol) proportional to a level of an input voltage corresponding to the input signal; a current controller (1600, 2600) comprising: a first voltage storage (1610, 2610) configured to store a voltage supplied from the voltage detector (1700, 2700) and configured to discharge its stored voltage to ground when the control voltage is a negative voltage; characterized by comprising a current controller (1600, 2600) comprising a second voltage storage (1630, 2630) connected to the first voltage storage (1610, 2610), and configured to store a voltage supplied from the first voltage storage (1610, 2610) and configured to discharge its stored voltage; a switch (1640, 2640) connected to the second voltage storage (1630, 2630), and activated by a driving signal to discharge the stored voltage of the second voltage storage by applying a ground voltage to the second voltage storage (1630, 2630); and comprising a current control signal generator coupled to the second voltage storage (1630, 2630), and whereby the current control signal generator is configured to generate a current control signal according to a value and gain of the voltage of the second voltage storage (1630, 2630); a second reference voltage supplier (1800, 3800) configured to supply the second reference voltage according to the current control signal; and a power factor compensation circuit configured to control a duty ratio of the driving signal according to a level of the current control signal, and control a peak value of a primary current in the main transformer (1300, 3300) according to a level of the second reference voltage. a main transformer (1300, 3300) configured to transform an input signal to supply the transformed input signal to an LED group (1400, 3400); a voltage detector (1700, 2700) configured to supply a control voltage (Vcontrol) proportional to a level of an input voltage corresponding to the input signal; a current controller (1600, 2600) comprising: a first voltage storage (1610, 2610) configured to store a voltage supplied from the voltage detector (1700, 2700) and configured to discharge its stored voltage to ground when the control voltage is a negative voltage; characterized by comprising a current controller (1600, 2600) comprising a second voltage storage (1630, 2630) connected to the first voltage storage (1610, 2610), and configured to store a voltage supplied from the first voltage storage (1610, 2610) and configured to discharge its stored voltage; a switch (1640, 2640) connected to the second voltage storage (1630, 2630), and activated by a driving signal to discharge the stored voltage of the second voltage storage by applying a ground voltage to the second voltage storage (1630, 2630); and comprising a current control signal generator coupled to the second voltage storage (1630, 2630), and whereby the current control signal generator is configured to generate a current control signal according to a value and gain of the voltage of the second voltage storage (1630, 2630); a second reference voltage supplier (1800, 3800) configured to supply the second reference voltage according to the current control signal; and a power factor compensation circuit configured to control a duty ratio of the driving signal according to a level of the current control signal, and control a peak value of a primary current in the main transformer (1300, 3300) according to a level of the second reference voltage.