近代中国的大都市几乎都有一块三教九流云集、众相纷呈的“杂吧地”。历史悠久的北京城的内、外城之间存在一种上、下半身的隐喻关系。这种隐喻关系尤其明显地体现在同处于北京南北中轴线的紫禁城和天桥之间。北京城市空间这种生理学上的特征同时也与在这两部分都市空间中生活的人形成共生与互显的关系。本文将描述近代北京城的杂吧地——天桥空间属性的形成,说明在相关行为表演的基础上、在言语叙述等规范的张力下,人们对于天桥地方感觉结构的形成过程。在此基础上,从方法论角度,进一步说明有着“下体”特征的本土表述“杂吧地”对于研究中国都市所具有的价值理性,和用生理学眼光研究城市空间及生活在其中的异质性群体的意义,以及现代都市泛滥的“下体”特征。 Almost all of China’s modern metropolises have a very close relationship with each other in many ways and every one has their own characteristics. There is a metaphorical relationship between upper and lower body between the inner and outer cities of the historic Beijing city. This metaphorical relationship is particularly evident between the Forbidden City and the flyover in the north-south axis of Beijing. The physiological characteristics of urban space in Beijing also form a symbiotic relationship with each other in the urban space in these two parts. This article will describe the formation of the spatial attributes of the flyover in the modern Beijing city, and illustrates the formation process of the local sensory structure of the flyover under the tension of normative language such as speech narration. On this basis, from a methodological point of view, this article further illustrates that the local expression “Bar Area ” has the value rationality of studying Chinese cities and the urban space and living in them with the view of physiology The significance of heterogeneous groups, and the “underbody” features of modern urban flooding.