We first report the pure HxMoO3 nanobelts as anode for lithium-ion batteries by a facile hydrothermal with ammonium heptamolybdate tetrahydrate ((NH4)6Mo7O24∙4H2O) and hydrochloric acid (HCl). Owing to hydrogen-doping, Mo5+ exists in the HxMoO3 nanobelt, which may release extra electrons. Therefore, the electric conductance of HxMoO3 nanobelt is enhanced greatly. Moreover, the content of hydrogen can’t be high, since the ordered structure deteriorates when amount of hydrogen increasing. The H0.28MoO3 nanobelts we designed exhibit outstanding specific capacity and rate performance. The stable capacity of 920mAhg−1 is obtained after 25 charge/discharge cycles at 100mAg−1. At high current densities such as 1, 2, 5 and 10Ag−1, the H0.28MoO3 electrode delivers specific capacities of about 600, 500, 420, 300mAhg−1, respectively. Even after 450 charge discharge cycles at 1Ag−1, the performance of our materials can maintain the capacity of about 550mAhg−1. Furthermore, we provide more discussion about the lithium storage mechanism of HxMoO3 nanobelts through ex situ XRD and FESEM. By comparing HxMoO3 with different X, we find that low content of hydrogen can greatly improve the performance of α-MoO3 electrodes in Li-ion batteries.