Here, we report a facile approach for synthesizing nanocrystalline Li4Ti5O12 by microemulsion at ambient temperature following by annealing treatment at 600 °C for 2 h for the first time. The X-ray diffraction, field emission scanning electron microscopy, transmission electron microscopy and nitrogen adsorption/desorption measurements are performed to characterize the structures and morphology of as-prepared sample. The as-prepared Li4Ti5O12 nanocrystalline around 30–50 nm in size and has high crystallinity, which displays excellent discharge/charge rate capability and cycling stability as anode materials for Li-ion batteries. More importantly, specific capacities for Li4Ti5O12 nanocrystalline achieved here are 173.7, 166.2, 136.2 and 130.2 mAhg−1 at 0.2, 1, 5 and 10 C after 50 cycles, respectively, indicating high potential application for Li-ion batteries.