Carbon and nitrogen, (C&N), co-modified hierarchical Li4Ti5O12 (LTO) particles with excellent perfomance in lithium-ion batteries were prepared via a facile synthesis with the proper modifying of C and N successfully reducing the polarization and enhancing the conductivity of LTO while also giving rise to Ti3+ sites due to the reduction ability of C&N. Together, with primary nanocrystals less than 10nm and a relatively high specific surface area (16.9 m2 g−1), as-prepared samples exhibit excellent electrochemical performance, such as a high capacity around 174.7 mAh g−1 at the current rate of 0.1C and reversible capacity over 171 and 150 mAh g−1 after 100 cycles at the current rate of 1 and 10C (1C=175 mAh g−1). More importantly, the optimal amount of C&N modifying in LTO was investigated for the first time. It was found that excessive modifying of C&N can introduce a lot of amorphous TiONx and also create undesirable Ti2+ to induce a structural transformation of LTO, directly leading to a low rate capacity.