Abstract: Seaport is more an economic system than a geographical space. The functions of modern seaport have changed from marine transportation initially to the node of international logistics center and the hub of global resource allocations now. As a polarized area,when its space is growing, the port exerts a great regional spatial impact on the port-city which is the port's directly linked hinterland, and so the port has become the basic driving force of port-city's spatial remodeling. As a typical example that relied upon a seaport to establish itself as a city and prospered from the seaport, Dalian's urban development has been closely related to the seaport's evolution. During the 100 years from the city's beginning to present, the whole developmental history of Dalian's port and Seaport is more an economic system than a geographical space. The functions of modern seaport have changed from marine transportation initially to the node of international logistics center and the hub of global resource allocations now. As a polarized area,when its space is growing, the port exerts a great regional spatial impact on the port-city which is the port's directly linked hinterland, and so the port has become the basic driving force of port-city's spatial remodeling. As a typical example that relied upon a seaport to establish itself as a city and prospered from the seaport, Dalian's urban development has been closely related to the seaport's evolution. During the 100 years from the city's beginning to present, the whole developmental history of Dalian's port and city boiled down to the process of neoteric and modern port economic development in our country and witnessed the history of port-city relationship. Taking the development of Dalian's port and city as an empirical case, this article puts the geographical spatial relationships of port-city into a multi-dimensional spatial frame, firmly grasps the interactions and transitional relations among "process-mechanism-pattern", and investigates the port evolution's geographical spatial effects at the city's scale. Generation, consolidation and continuous reinforcement of potential energy of the city's location in transportation in urban development, port industrial space growth and morphological evolution, promoting the formation of "Sunshine City" land use pattern, and development of Hub-and-Spoke traffic logistics spatial network with the characteristics of port and shipping harbor, are the four major aspects revealing the mechanism and manifestation of the effects of modern seaport on urban geographical space. This article draws two conclusions. On the one hand, the formation, strengthening and aggrandizement of seaport's potential energy of its location in transportation is the source power of seaport's spatial effect on city. The potential energy makes the port-vicinity belt to be the junction station of production factors, promoting regional growth. In the Supply Chain and information age, port's transformation from location advantage to logistics advantage lays the foundations for production factors' convergence in flow age. Contrary to traditional ports focusing on certain industries and foreign trade, modern seaports continuously strengthens integrated service function of logistics, information and so on. The urban regional spatial effect of modern seaport evolution can be described three aspects. (1) At macroscopic level, port evolution drives port-vicinity industrial spatial development and pushes forward the overall urban morphology evolution, which is the main approach and runs through the whole process of port city development. (2) At microcosmic level, formation of port-city's land-use pattern pushes forward the urban internal structure change and urban function optimization, which is a restriction mechanism. Although with the characteristics of port and shipping harbor are weakening when the harbors are relocating to elsewhere, the circular layer model of land use from single-center city or a new port-vicinity city has relative stability. (3) From the perspectives of time characteristics, logistics center is the principal function of a Third Generation port. Compared to traditional ports, the urban regional spatial effects of a modern seaport clearly have different characteristics. By Hub-and-Spoke space network of traffic and logistics, modern ports drive regionalization and networking of port industries and the evolution of its mother city's space, and finally transform seaport cities to resource allocation hubs of the world market.

Key words: Dalian City, Hub-and-Spoke logistics network, location potential of seaport, space of port industry, urban land use of port-city