Abstract: Following the reformation and open-door policy, the Changjiang River delta, one of the e-conomy developed coastal areas in China, shows that the city is being industrialized, the region is being urbanized, and the city and countryside are merging into an organic whole. In the recent twenty years, the economy of this delta has developed rapidly. At the same time, the regional infrastructure has been improved day by day; the social, economical, cultural and technological relations among cities have been reinforced; the urban district has spread from a point to a area by the way of agglomeration and axis-pattern extension; and the level of industrialization and modernization of the city has been heightened continually. Therefore, in the economy developed areas, the main features and the radical trend of the urban spatial evolution appear in the form that the city and the countryside merge into an organic whole owing to agglomeration, reciprocal attraction and reciprocal dispersion of the cities. This paper mainly studies the fundamental characteristics, dynamic mechanism, function variations and the trend of the urban spatial ex-pansion in developed areas, together with a lot of typical cases of cities in the Changjiang River delta.

Key words: urban spatial evolution, regional economic concentration, axis-pattern ex-tension