This paper proposes high energy-efficient IP network architecture with Giant Center Router and Optical Aggregation Network. User IP packets are aggregated and transferred to Giant Center Router through Optical Aggregation Network transparently by dynamic optical resource allocation. Giant Center Router is power scalable with an amount of traffic proportionally. Optical Aggregation network is realized by circuit switches, wavelength converters, and wavelength multiplexers/ demultiplexers. The proposed network scheme reduces the power consumption to 1/20-1/30 compared to the conventional Internet, realizes a network structure well suited to traffic centralization, and offers smooth migration from the conventional Internet.