Uniform FeCO3 cubes with edge length of ∼300nm were prepared by a facile one-step hydrothermal reaction and studied as anode material for lithium-ion batteries. Interestingly, the FeCO3 anode has an extremely high initial specific capacity of 1796mAhg−1. After cycling at a current rate of 200mAg−1 for 130 cycles, an excellent discharge capacity of 761mAhg−1 is still maintained. Moreover, the FeCO3 anode exhibits significant high-rate capability, e.g., ∼430mAhg−1 is obtained at a current rate of 1200mAg−1. The observation of the FeCO3 cubes represents an important development of realizing both high capacity and good cycleability in conversion type anode materials for lithium-ion battery at the same time. Such cheap, easy-to-make, and environmentally benign material is promising for practical deployment for lithium ion batteries anode.