近代中國的大都市幾乎都有一塊三教九流雲集，敢相紛呈的「雜吧地」。歷史悠久的北京城的內、外城之間存在一種「上半身」與「下半身」的隱喻關係。這種隱喻關係尤其明顯地體現在同處於北京南北中軸線的紫禁城和天橋之間。北京城市空間這種生理學上的特徵同時也與在這兩部分都市空間中生活的人形成共生與互顯的關係。本文將描述近代北京城的雜吧地天橋空間屬性的形成，說明在中目關行為表演的基礎上，在言語敘述等規範的張力下，人們對於天橋地方感覺結構的形成過程。在此基礎上，從方法論角度，進一步說明有著「下體」特i致的本土表述雜吧地對於研究中國都市所具有的價值理性，和用生理學眼光研究城市空間及生活在其中的異質性群體的意義，以及現代都市泛濫的「下體」特徵。

In modern China, most metropolises contained areas where people of all walks of life would mix together. Such places were usually referred to as “zabadi” (literally “motley areas”). In China’s venerable capital of Beijing, the relationship between the inner city (neicheng) and outer city (waicheng) was conceived of in terms of urban physiology as resembling the upper and lower parts of the human body. Such a metaphor finds clear expression in the centrally located area between the Forbidden City and the Sky Bridge (Tianqiao) district, both of which lie along Beijing’s meridian. During the modern era, a relationship of mutual growth and reflection shaped the historical development of these two areas and their residents. This paper describes the formation of the spatial characteristics of Beijing’s Sky Bridge district, using interrelated action performances and standards of language to explore how its residents’ feelings of structure have emerged. In addition, it adopts a methodological point of view to interpret the meaning and value of zabadi, which is expressed in indigenous terms for private parts (literally “xiati” or lower body) that portray modern Chinese urban space from a physiological view expressed by its heterogeneous inhabitants.