This paper reports the study on thermal reactivity of spinel lithium titanium oxide (Li4Ti5O12) material. Thermalgravimetry and Differential scanning calorimetry (TG/DSC) is used to investigate the relevant profiles of Li4Ti5O12 and Li7Ti5O12 electrodes. TG results show Li7Ti5O12 electrode material has higher thermal weight loss, which is 26.7% below 600 °C, significantly larger than that of 20.4% for Li4Ti5O12 electrode. Moreover, the onset exothermal temperature for Li7Ti5O12 electrode material is lower and total exothermal energy is higher. Fourier transform infrared (FT-IR) spectroscopy confirms that more CO group containing compound are generated on Li7Ti5O12 electrode. One species can be decomposed below 460 °C, and the other one can be decomposed below 600 °C. It is conclude that the aforementioned two species leads to higher thermal reaction of Li7Ti5O12 electrode.