中文摘要：

京津地区区域城市自先秦以来萌芽阶段的缓慢发展，自秦汉以后，历经曲折的演进过程，先后经过松散式、单核心紧密化和单核心极化式以及双核心并列式等四个发展阶段，在空间布局上呈现出由山前地带向滨海地带梯度推移的发展规律。经过这四次发展，京津地区区域城市最初西重东轻的分布格局得到改变，区域城市空间分布日趋均衡。区域中心城市从不稳定发展到单一中心结构确立，近代以来又发展为双中心结构，区域城市在空间上呈现出两个分别由中心城市和周边城市环带形成的双“点一环”状组团分布的空间格局。

英文摘要：

In this paper, the evolution about development and distribution of the urban group in Beijing and Tianjin area has been analyzed. This paper shows that the urban group in Beijing and Tianjin area has developed in four important stages since Qin Dynasty. In each stage the development and distribution of the urban group took on a new look. In the first stage, the number of the urban group declined since East-Han Dynasty, and most cities ditributed in the hillside zone. In the second stage, the number of the urban group grew quickly and most cities distributed in the middle zone. In the third stage, the number of the urban group stood still and the cities in the seaside zone grew quickly. In the four stage, Beijing and Tianjin become the two centers in this area and the urban group develops in balance. So we come to the conclusion that with the development of Beijing and Tianjin area, the distribution of the urban group spread step by step from hillside zone to the middle zone, and then from the middle zone to the seaside zone in space. The urban group developed from one core into two cores, and the distribution of Beijng and Tianjin area are composed of two small urban groups centered on these two cores. In the future, the development of the urban group will come into a new stage.