Future Internet will be a hierarchy topology. To guarantee peer-to-peer QoS, QoS-based routing protocolwill be adopted. Considering scalability and security, topology information used by routing protocol should be com-pressed before distribution in network. Routing protocol would route the packets without knowing the complete net-work topology information. This article investigates several different topology aggregation schemes and their applica-tion area. We also compare the performance of different topology aggregation schemes under different topology struc-tures and update policies.