A composite of porous carbon coated Li4Ti5O12 was prepared by a hydrothermal synthesis and high-temperature activation method. The microstructure and electrochemical properties of the composite were investigated. The results show that Li4Ti5O12 is completely coated on the porous carbon layer. Meanwhile, the surface pores of Li4Ti5O12@porous C composite are evenly distributed, and the carbon layer thickness is approximately (8.5±3.6) nm. The discharge capacity at first cycle is 363 mAh/g, which is approximately twice greater than that of pure Li4Ti5O12. The AC impedance value of Li4Ti5O12@porous C composite decreases, which is only the half of that of pure Li4Ti5O12. The discharge specific capacity of Li4Ti5O12@porous-C composite is 251 mAh/g and the retention rate is 97.7 % after 200 cycles (i.e., the specific capacity of pure Li4Ti5O12 is 143 mAh/g and the retention rate is 94.7%), the discharge specific capacity is nearly doubled, especially when the rate test is carried out at different discharge rates. The reversible capacity is twice greater than that of Li4Ti5O12. The porous carbon coated modification of Li4Ti5O12 can increase the specific surface area and the electron transfer rate for the higher electrochemical properties.