Amorphous aluminum silicate films with film thicknesses of 0.5-2.7 mum were prepared on silicon substrates by low-pressure metalorganic chemical vapor deposition. This deposition was conducted using aluminum tri-sec-butoxide as the aluminum source and tetraethyl orthosilicate or hexamethyldisilazane as the silicon source. The choice of different silicon sources is based on their reactivity. The study of growth kinetics is based on the variation of growth rate with deposition temperature and reactant input. These two systems showed big differences in growth kinetics and film composition.