Abstract: An enhanced inter-domain routing aggregation algorithm is proposed to strengthen routing aggregation behavior and constrain route advertising scope, based on the properties of Internet hierarchical structure and the relationship between autonomous systems. A prototype system implementation algorithm is thus provided, in which all the required data will be got from the interior of autonomous systems without global coordination data. The algorithm proposed can efficiently avoid the negative impact of aggregation on load balancing and link redundancy. Testing data statistics and analysis show that this algorithm can evidently reduce the routing table size so as to relax the pressure due to high-speed expansion of routing table at present and enhance the Internet expandability.