In order to overcome the problem that the low conductivity and high content of graphitic N will lead to serious irreversible capacity loss, magnesiothermic denitriding method was employed to fabricate nitrogen deficient g-C3N4 (ND-g-C3N4). By controlling the reaction conditions, ND-g-C3N4-675 with optimal electrochemical properties was obtained. The ND-g-C3N4-675 has thinner two-dimensional porous structure, with high specific surface area and good conductivity. The ND-g-C3N4-675 showed superior cyclic stability and rate capability (After 500 cycles under 1000 mA·g?1, 2264.9 mAh·g?1 was obtained). Moreover, it presented high initial coulombic efficiency (42.2％).