隨著人類文明的進展，全球都市化的程度亦日益加深。關於都市形成與規模的理論，一般認為有兩種典範：一種是大規模開發商在國家土地市場的競爭模型；另一種則是經濟上聚集效果的自我組織模型。研究上多從聚集經濟、規模經濟等效果來解釋都市的人口成長；另一方面，隨著都市擴張而不斷增加的各種成本，則是抑制都市成長的阻力。這些助力與阻力的消長，決定了都市的人口規模動態。2011年，全球共有26個人口超過1000萬的巨型都市，其中就有15個位於亞洲，並包含了前六大；另外，相對於西方巨型都市的穩定規模，這些亞洲巨型都市的人口，仍然隨著經濟發展而不斷地快速增加。這些現象說明了原先用以解釋都市規模的經濟理論，在亞洲巨型都市的應用上，可能有補充的空間。本文認為：亞洲文化中，居民遷徙到大都市「追尋夢想」，「渴望成功」的趨力，可以補充解釋亞洲巨型都市的人口成長動態，也能部分說明東西方都市人口密度的差異。

With the development of human civilization, the extent of urbanization rises. There are two paradigms of city formation and size. One is the competitive model of large-scale land developers operating in national land markets, and the other is the self-organization model of agglomeration. Usually, researchers use the economies of agglomeration and scale to explain urban population growth. On the other hand, the increasing costs along with urban expansion constrain the growth of city. Thus the dynamic city size is determined by the net effect of positive and negative influences. In 2011, there are 26 megacities which their populations are over ten millions all over the world. Especially, 15 of them, including the top six, are in Asia, and the sizes of most Asian megacities are continuously growing over time. The phenomenon implies that the application of current theory regarding city size may have some gap in Asian megacities. This research attempts to fill the gap by bringing the "dreaming pursuing" factor of immigrants into the analysis of giant Asian megacity size. And the cultural explanation could also illustrate the variation of population density between East and West.