The origin of the word "male external genitals(Zongjin)" is coming from Inner Canon of Huangdi(Huangdi Nei Jing).This article synthesized the theories of past dynasties' doctors.It made a systemic statement on "male external genitals" in terms of the concept,physiological functions and the contacting effect with correlated meridian and vessels for the first time,so as to enrich the theory of visceral manifestations in TCM.Meanwhile,it also pointed out the significance and specific application of the theory that treating impotence based on "male external genitals",thereby provided a new view of treating "male external genitals" in TCM clinic.