This paper presents new estimates of the development of the urban population andthe urbanization ratio for the period spanning the Song and late Qing dynasties. Urbanizationis viewed, as in much of the economic historical literature on the topic, as an indirectindicator of economic development and structural change. The development of the urbansystem can therefore tell us a lot about long-term trends in the Chinese economy between1100 and 1900. During the Song the level of urbanization was high, also by internationalstandards – the capital cities of the Song were probably the largest cities in the world. Thisremained so until the late Ming, but during the Qing there was a downward trend in the levelof urbanization from 11–12% to 7% in the late 18th century, a level at which it remained untilthe early 1900s. In our paper we analyse the role that socio–political and economic causesplayed in this decline, such as the changing character of the Chinese state, the limited impactof overseas trade on the urban system, and the apparent absence of the dynamic economiceffects that were characteristic for the European urban system.