A plug structure of light emitting AC electric power cord is disclosed, wherein a plug body is internally combined with a circuit board which comprises at least a circuit device and at least two conductive board, and the circuit device includes at least two light emitting diodes (LEDs) respectively corresponding to a light guiding line within the electric power cord; accordingly, when the conductive board transfers AC power to the two LEDs, the circuit device can controls such two LEDs to glow at different moments in order to create an image persistence difference of one parallax thereby allowing human eyes to generate the image persistence effect in vision such that the light guiding line may present a visual perception of light flowing.