Spinel Li4Ti5O12 (LTO) has been intensively investigated as promising anode materials for lithium-ion batteries (LIBs) due to its remarkable structural stability and excellent safety. In this paper, unique LTO nanosheets with porous microstructure are successfully prepared for the first time by a facile approach without any additives and template under hydrothermal conditions following calcination. Particularly, compared with traditional LTO microspheres and smooth LTO nanosheets, the newly prepared mesoporous LTO nanosheets demonstrate extra surface lithium storage reaction and much improved electrochemical performances, delivering ultrahigh reversible capacity of 169 mAh g−1 at 1C and superior rate performance of more than 140 mAh g−1 at 30C between 1.0 and 2.5 V vs. Li+/Li. The beneficial surface lithium storage is mainly attributed to its advanced microstructure, which can facilitate the transfer of lithium-ions and electrons. The exceptionally improved electrochemical performance of the mesoporous LTO nanosheets will undoubtedly make this microstructure attractive for high performance electrode materials of LIBs.