Abstract: During the process of urbanization in our country,it has always been a contentious topic whether to develop big cities or small cities and towns.It’s quite necessary for us to look back and reflect theoretically and practically.Principles issued by the central government in the twelfth "Five-year Plan" pointed out specifically that our country should rely on big cities,focusing on medium and small cities,form city agglomeration with a large radiant effect,so as to promote the coordinated development of medium and small cities and small towns.They also emphasized the enhancement of public services and inhabitancy in small towns by softening the terms for the settlement of migrants.The strategic position of small towns has never altered.

Key words: city agglomeration, big and medium cities, small towns, special function