An electronic device for enhancing voltage driving efficiency for a source driver and a liquid crystal display (LCD) monitor is disclosed. The electronic device includes a reference voltage generator, a plurality of first coupling lines, a second coupling line wider than the first coupling lines, a data statistical unit and a reference voltage modulating module. The reference voltage generator generates a plurality of grayscale reference voltages. Each first coupling line and the second coupling line are utilized for transmitting one of the grayscale reference voltages. The data statistic unit statistically calculates a plurality of grayscale data values to generate a statistical result indicating a grayscale reference voltage corresponding to the most of the grayscale data values among the grayscale reference voltages. The reference voltage modulating module adjusts transmission relationship between the grayscale reference voltages and the first coupling lines and the second coupling line according to the statistic result.