Free-standing, two-dimensional MoO3 nanosheets were successfully fabricated via a liquid-phase exfoliation method. The resultant MoO3 nanosheets possess thin feature, large aspect ratios and well-defined single-crystalline structure. Such unique features are favorable for the facile access of lithium ions to the electrode materials for lithium storage. As a consequence, the as-prepared MoO3 nanosheets not only exhibit a very high capacity of 1427 mAh g^-1 in the initial discharge process, but also deliver a high reversible capacity of 1115 mAh g^-1 after 30 cycles. More importantly, this nanosheets possess excellent high-rate performance, holding great promising to be applied as anode materials for high-power lithium ion batteries.