High content structural aluminum incorporated MCM-41 molecular sieves were synthesized via a hydrothermal method using cetyltrimethylammonium bromide and cetyltrimethylammonium hydroxide as mixed templates. This method provides Al-MCM-41 of different Si/Al atom ratios from 3 to 100 corresponding to 0.91–30.3mol% Al. Characterization using X-ray diffraction and nitrogen adsorption measurements revealed that Al-MCM-41 prepared by this method had a highly ordered structure of pore arrays. Solid state 27 Al MAS-NMR investigation showed further that the Al atoms were in tetrahedral coordination even at a high level of aluminum (30.3mol% Al). In order to distinguish the new method, the samples prepared by the conventional hydrothermal method were also investigated and compared with the former.