For next generation Li-ion batteries, advanced electrode materials with high energy densities are mightily important issue. Since the partial oxidation of Sn with Li2O to form SnO x was demonstrated upon delithiation in SnO2 anode, the additional conversion reaction has contributed that the theoretical capacity of SnO2 can be extended from 783 to 1494 mAh g−1. Herein, with the design of additional conversion reaction, we discuss key factors for high electrochemical performances of the SnO2 anodes through comparative analysis between nano-structured mesoporous SnO2 and conventional bulk SnO2, based on synchrotron radiation-based techniques, quantitative analysis of extended X-ray absorption fine structure spectra, and bond strength calculation. In this way, we demonstrate that the mesoporous SnO2 has a nano-engineered structure with the weakened Sn-O bond strength for inducing the enhanced reversible conversion reaction as well as the facilitated electrochemical reaction, and a void structure for relieving the severe volume changes during lithiation/delithiation. Consequently, excellent electrochemical performance through the additional reversible conversion reaction is obtained in the mesoporous SnO2. Insight from this research enables important advance in the development of metal oxide-based anode materials by making irreversible reaction reversible, providing a realizable strategy for the design and creation of high-energy storage devices.