The present invention provides a driving circuit for driving a color display to display black-and-white/grayscale images and comprises a data conversion circuit and a driver. The data conversion circuit receives input data transmitted by a microprocessor. The format of the input data is a black-and-white/grayscale format. The data conversion circuit converts the input data for producing output data. The format of the output data is a color format. The driver receives the output data and drives the color display to display the black-and-white/grayscale image. The driving circuit will convert the input data transmitted by the microprocessor with limited transmission capability and produce color output data for driving the color display to display the black-and-white/grayscale image. Accordingly, by using the driving circuit according to the present invention, an electronic device with limited transmission capability can work with the color display to display black-and-white/grayscale images.