Porous glasses containing different silica species have been prepared by acid leaching of a phase-separated sodium borosilicate glass with dissolved silica in the alkali-rich berate phase. The structure and texture properties of these materials, composing of a mesoporous system formed by colloidal silica inside the original macropores of the porous glass, have been investigated using Scanning Electron Microscopy (SEM), Low Temperature Nitrogen Adsorption, Mercury Intrusion and Small Angle X-ray Scattering (SAXS). The SAXS curves for these porous glasses have been analyzed applying the theory of chord length distribution. A good agreement between the results of the pore characterization of the colloidal silica using nitrogen adsorption and SAXS has been found. (C) 2001 Elsevier Science B.V. All rights reserved.