Benefiting from the growth of techniques of dynamic page generation, the amount and the complexity of Web pages increase explosively. The structures of Web pages which are dynamically generated by the same templates are thus similar to one another and are usually assembled by a set of fundamental information clusters These neighboring information clusters usually represent the similar semantics and form a larger cluster with the more generalized information. The hierarchical structure generated by information clusters in a bottom-up manner is called the information hierarchy of a page. In this paper, we study the problem of mining the information hierarchies of pages in Web sites to recognize the information distribution of pages within the multi-level, multi-granularity configurations. Explicitly, we propose an information clustering system that applies a top-down information centroid searching algorithm and a multi-granularity centroid converging process on the document object model (DOM) trees of pages to build the information hierarchies of pages. Experiments on several real news Web sites show the high precision and recall rates of the proposed method on determining information clusters of pages and also validate its practical applicability to real Web sites.