MnC2O4 precursor was prepared by a precipitation method, and then porous MnO@C composites were obtained by mixing MnC2O4 precursor with different amounts of glucose and sintering at different temperatures. The influences of carbon content and crystallinity on the electrochemical performance of MnO@C were investigated. Galvanostatic charge–discharge test results showed that the MnO@C sample “1.2,700” has the largest specific capacity among all samples, which can reach high specific discharge capacity of 1691mAhg−1 at the current density of 100mAg−1 after 200 cycles. Even at the high current density of 1600mAg−1, a remarkable discharge capacity of ∼630mAhg−1 can still be delivered, demonstrating a good rate capability. The excellent electrochemical performance can be ascribed to porous structure, good crystallinity and proper amount of carbon coating. This facile method can be applied to the large-scale synthesis of high performance transition metal oxide@carbon composite electrode materials.