The purpose of this study is to give a comprehensive and coherent account of the various senses of tiao by analyzing it in terms of cognitive grammar. Although Tai and Wang 1990 have investigated tiao, the discrepancies such as the use of tiao in yi tiao haohan ‘an extremely independent man’ have not been touched upon. The present study will cover as many synchronic data as possible and treat Tiao as a complex category with a schematic network in which its various senses are shown to be related to one another in a cognitively motivated way. The prototype of tiao will be explored, and the (1) cognitively motivated extensions, e.g., yi tiao tui ‘a leg’, (2) pragmatic-functionally motivated extensions, e.g., yi tiao shoupa ‘a handkerchief, (3) metonymically motivated extensions, e.g., yi tiao kudai ‘an elastic for a pair of trousers’, and (4) metaphorically motivated extensions, e.g., yi tiao xin ‘a common ultimate goal’ will be discussed. The result of this study will present a more convincing, reasonable, and comprehensive explication of the internal system of the category tiao.