A method for power saving of display devices is provided. The method includes: while displaying a frame on a display, providing a representative data luma according to a plurality of original data lumas of a plurality of pixels of the frame, mapping a representative data luma value of a frame and a corresponding original drive value to a target display luma value according to the display characteristic, providing a power-saving data luma and a power-saving drive by mapping the target display value to a reference curve to display the frame.