Abstract: Centrality studies of complex network aim at finding out the centralization nodes in the network. The centrality measurement of the complex network can accurately and quickly find out the centralization nodes in a complex and large-scale network. Based on this, the network can be managed effectively. The problems of the centrality measurement of Internet at AS-level were studied. Based on the AS-level measuring data of CAIDA in Feb, 2011, the degree centrality, betweeness centrality and closeness centrality of Internet were analyzed and calculated, and the relationship among them was further explored. It was concluded that all the three measurements can find the centrality nodes in the network effectively. But the closeness centrality can reflect the global network more accuracy than the degree centrality and betweeness centrality.