中文摘要：

城市群是新时期城市化推进的主体形态，城市群研究的核心问题是其形成机制。基于对国外有关城市群形成机制的研究文献所进行的分类综述，得出城市群的形成既是居民--厂商主体区位选择的微观过程，又是基于垂直联系的产业演化过程，同时还受到地方政府主体的影响。城市群形成机制是自组织和有组织共同作用的过程。

英文摘要：

Urban agglomeration is the main form of ur- banization. The core of urban agglomeration research is formation mechanism. This article reviews the formation mechanism of urban agglomeration. Its formation is based not only on the region choice by firm and household, but also on the industry evolution by vertical linkage. Besides, local government plays an important role in the process. The formation of urban agglomeration is not only self - organization process, but also hetero - organization process.