Vanadium oxides were synthesized by hydrothermal synthesis with vanadium pentoxide(V2O5) and sodium sulfite anhydrous(Na2SO3). The effects of preparation factors including pH, fullness, reaction temperature, the amount of sodium sulfite anhydrous were systematically studied. The valence, phase and morphology of vanadium oxides were analyzed by chemical titration, X–rays diffraction(XRD), scanning electron microscopy(SEM) and differential scanning calorimetry(DSC). The results showed that the content of vanadium oxides could reach 98.5% under the optimal conditions of pH of 3, fullness of 0.7, reaction temperature of 250℃, n(V2O-5):n(Na2SO3) of 1:1.2 after purification. The total yield is 85.4%. The product is high purity needle-like VO2 powder with uniform morphology and fine crystalline. The product's diameter is about 80～100nm, the length is about 3μm, and the product is changed from B phase to M phase at 69.0℃after calcined at 800℃for two hours.