In the present work, the aqueous slurry containing 30 wt% solid aluminum particles was prepared, using paraffin oil and oleic acid dispersant and surface active agent respectively. The results showed that no obvious aluminum particle sediment was observed even after being kept it at room temperature in air up to 15 days. The hydrogen generator based on the reaction of the aluminum slurry and sodium hydroxide aqueous solution was manufactured and could supply a maximum hydrogen flow rate of 20 NL/min. The dew point of the hydrogen from the generator was lower than -40oC, indicating the high purity of the as-obtained hydrogen. As expected the X-ray diffraction patterns revealed that the byproduct was bayerite.