For carbon-based anode materials of lithium-ion batteries, guaranteeing high surface area while maintaining developed mesoporosity remains a formidable challenge because the diffusion of electrolyte within mesopores is the rate-performance-limiting step. Herein, mesoporous activated carbon aerogel (MACA) is prepared based on the pore formation and widening effect of H3PO4. The as-prepared MACA demonstrates a high specific surface area (SSA) of 2161 m(2) g(-1) with an extremely high mesopore ratio of 92 %. This well-defined mesopore-dominant nanostructure coupled with high SSA can provide large ion-accessible SSA for Li+ storage reactions as well as facilitate better mass transfer capability, especially at high charge-discharge rates. In consequence, MACA shows a much higher specific capacity of 610 mAh g(-1) at 0.1 A g(-1) and an excellent high-rate performance in contrast to other amorphous carbon materials and commercial anode of graphite. These encouraging results reveal the promising application of MACA for high-performance lithium-ion batteries.