The method for increasing the dense of foamable precursors in the process of manufacturing the aluminum foam by powder metallurgy route has been studied. The factors which have influence on the dense of foamable precursors in the process of preparation and the densification process have been discussed. The influence of sintering temperature and sintering time on the structure in the foamable precursors and the densification has also been discussed. The main discussion is focused on the influence of the sintering on the variations of magnesium particles and the quality of the aluminum foam manufactured by powder metallurgy. As for the matrix material which particles size is between 75~150μm, the foamable precursor which is sintered at 450℃ after cold compression would increase its density and the continuity of the matrix. The sintering time should not be less than two hours,therefore the size of the magnesium particle will be twice or even three times larger than that for the one that is not sintered. The results reveal that high quality aluminum foams could be obtained by uniaxial cold compaction under the pressure 400MPa with sintering at 450℃ for two hours. In this way, the quality of the aluminum foam could be better than the one without sintering.