Recently, mesoporous nanoparticles have been gradually attracted more attention in the field of materials and heterogeneous catalysis.Among the metal elements, titanium has been most studied because titanium-containing mesoporous molecular sieves are highly active in many selective oxidations.However, the particle size of mesoporous molecular sieves is generally scaled in micrometer, which greatly limits the diffusion of reactants in catalysis.In our work, Ti-MCM-41 and mesoporous titanosilicate nanoparticles with the size less than 100 um were successfully prepared using cationic polymers via hydrothermal synthesis method.