Abstract: Bismuth-containing composite materials based on high-silica porous glasses (PGs) of various types are prepared. Their structural parameters and electrokinetic potential in 10 ^–2 М KNO ₃ solutions in the pH range 1.5–8.5 are studied. The results are compared with the analogous properties of matrices not modified with bismuth oxide, as well as the pH dependence of the zeta-potential for SiO ₂ particles and the sols of synthesized and industrial bismuth(III) oxide. It is determined that modification of larger-pore particles not containing secondary silica with bismuth(III) oxide results in the deviation of the form of the ζ–рН dependences from those intrinsic for high-silica PG and SiO ₂ particles.