本文研究了产业集群发生的机制，进而对集群发生的两个“剑桥现象”作了解析，从而得到关于产业集群的一些规律认识：1知识溢出破坏了正常的霍特林过程，使得区域发生集群。集群的紧密程度与知识溢出的阻尼呈反比。当产品成本逼近价格并且低于价格容易发生集群。2中小企业较大企业容易发生集群。3企业集群存在一个空间最佳规模，它由人才工资、土地租金、土地供求关系等决定，空间规模不可能任意发展。4发生集群的是劳动密集型企业或者是占地较少的人才密集型高科技企业。传统大工业难以发生集群。5集群发生具有涌现性质，是一种复杂性现象。  

The mechanism of industry cluster is studied, and two cases of cluster process known as Cambridge phenomenon are analyzed. Based on this, some disciplinary understandings are found as below. Firstly, knowledge spillovers destroy the normal Hotelling process, and lead to regional industry cluster. The density of cluster is inversely proportional to the damp of knowledge spillovers. When production costs increase close to its price, the industry cluster is easy to appear. Secondly, it is easier for small and medium-sized enterprises to cluster than for large-sized enterprises. Thirdly, there is an optimal spatial scale, which depends on workers’ wage, rent of land, supply-demand relationship of land, etc. The scale of a cluster cannot develop wantonly. Fourthly, labor intensive firms and human resource intensive firms occupying small sized land are more inclined to cluster. On the other hand, traditional large-sized companies are hard to cluster. Finally, industry cluster is a kind of complex phenomenon, which has the character of emergence.