Several xSiO 2 -xAlPO 4 -(100-2x)TiO 2 catalyst supports were investigated with regard to their structural and textural properties. Their textural properties were found to depend on their chemical composition. Low titania content (5 mol%) led to an increase of the BET surface area, whereas a higher titania content virtually did not modify the BET specific surface area, but did lead to a decrease of the pore volume. X-ray diffraction (XRD) and infrared (IR) data are in accordance with a good dispersion of titanium (up to 15 mol%) in the matrix. X-ray diffraction showed that the silica-aluminum phosphate matrix was present as an amorphous phase in all catalysts calcined at 973 K, but crystalline domains of anatase were found in supports containing 20 mol% or more titania.