Micro/mesoporous composite material is prepared via reaction of zeolite Beta seeds solution and mesoporous precursor solution under hydrothermal conditions. The resulted micro/mesoporous composite contains nanoparticles with a mean radius of about 90 nm, while pure zeolite Beta and MCM-41 have particles with size of about 50 and 230 nm, respectively. The presence of highly cross-linked silicon framework walls and tetrahedrally coordinated aluminum in the framework structure are confirmed with solid-state 29Si and 27Al NMR investigations. Adsorption measurements show the presence of micropores, mesopores and high interparticle porosity due to the nanometer-sized particles in the micro/mesoporous composite. Various techniques such as dynamic light scattering, scanning electron microscopy, X-ray diffraction, FT-IR, NMR spectroscopy and nitrogen sorption measurements were carried out in order to investigate the properties of the prepared material.