Abstract: The Internet topology, especially the AS-level topology, is the hotspot of the research. We can comprehend well the inner connective mechanism of the network by researching the evolvement trend of the Internet topology. In this thesis, the research task is based on the massive data authorized by CAIDA(The Cooperative Association for Internet Data Analysis) Skitter project and the data's time span is from January 2004 to June 2008. This paper introduced the essential basic conceptions first, then carried out the evolvement analysis of the node average degree, the maximum node degree, the average degree of the top-degree node, the connectivity of rich-club and the clustering coefficient. It is discovered that the affect of the top-degree nodes and the connectivity between the top-degree nodes is descended by the time movement. However the network puts up still obvious rich-club character and clustering coefficient totally.

Key words: AS-level, Internet topology, Degree, Connectivity, Evolvement analysis