Aluminum (Al) alloys with gallium (Ga) and indium (In) were prepared via mechanical alloying technology. The hydrolysis reaction between the Al alloys and pure water was studied to observe the hydrogen yield evolution. The results obtained by X-ray diffraction, scanning electron microscopy and energy dispersive spectroscopy show that Ga and In elements mainly exist in the alloy in the forms of dissolution and precipitated phases, respectively. The dissolution of Ga and In can improve the hydrogen yield of Al alloy by enhancing the activity of hydrolysis reaction. Moreover, the quantity and distribution of precipitated phase determined by ball milling time directly influence the hydrogen yields, and the Al alloy with appropriate number and uniform-distributed precipitated phase can react with 0 _oC pure water to produce 1132.8ml/g hydrogen.