With the technology and the efforts to develop safety applications, vehicles are already equipped with a certain degree of drive-by-wire system for use in driver assistance systems. However, for self-driving system, drive-by-wire should be designed for more critical scenarios. This article will discuss the drive-by-wire technology based on the development of the self-driving vehicle of ITRI. We will also and introduce throttle-by-wire, brake-by-wire, shift-by-wire, steer by wire, and their advantages and applications, respectively.