Central Business District (CBD) is not only is the central district of a city, but also the product of economic and the third industry development. Meanwhile, in the metropolitan of China, there are large number requirements of the CBD construction for sub-regional cities. In Yangtze River Delta metropolitan, the cities such as Ningbo, Suzhou, Wuxi, Jiaxing, Huzhou, Shaoxing, Zhoushan, Yangzhou, Changzhou, Taizhou, Zhenjiang, Nantong, most of which GDP have reached 1000 billion Yuan and owned the initial economic base for the CBD construction. However, compared with the regional city or the world city, the sub-regional city’s CBD has the differences in scale, spatial form, the development operation and traffic patterns. In this paper, the sub-regional city in Yangtze River Delta— Changzhou is taken as research object，the CBD construction theory and urban design method are proposed to provide reference for similar area .