A comparative INS study of the vibrational spectra of the water adsorbed on three dispersed amorphous silicas(aerosil, silica gel and aerogel) is presented. The spectra have been obtained as differences between the spectra of the "as-prepared" air-dry samples and the air-dried ones. The spectra of the adsorbed (a) and/or retained water are separated. the a-water spectra in the above three cases are substantially different indicating the different configurations of the sample surface active centers. This phenomenon is suggested to be caused by the polymorphism of the "as-prepared" material cores, due to the polymerization peculiarities when manufacturing the products by different technologies. © 1992.