SiO2/Poly(3-aminophenylboronic acid) (PAPBA) composites were synthesized under different experimental conditions, using ultrasonic irradiation method. Polymerization was carried out in the presence of sodium fluoride and D-fructose to anchor 3-aminophenylboronic acid groups on to SiO2 surface. The SiO2/PAPBA nanocomposite prepared by NaF and D-fructose in the polymerization medium was found to show different morphology, electrical properties, thermal behavior and structural characterization in comparison to the nanocomposites prepared under other conditions. Ultrasonic irradiation minimizes the aggregation of nanosilica and promotes anchoring of PAPBA units over SiO2 surface. The morphology of PAPBA/SiO2 nanocomposite was investigated by using transmission electron microscopy, UV-visible spectroscopy; thermogravimetric analysis, Fourier transform infrared spectroscopy, and X-ray diffraction analysis were used for characterization. Transmission electron microscope of the nanocomposites observation shows that SiO2/PAPBA composite, prepared with D-fructose and NaF under ultrasonication has a core-shell morphology. The thermal and crystalline properties of core-shell SiO2/PAPBA nanocomposite was prepared via ultrasonication method is different from the SiO2/PAPBA nanocomposite prepared via conventional stirring method, in which SiO2 nanoparticles are submerged in PAPBA. Conductivity of the composite prepared via ultrasonication shows around 0.2 S/cm. (c) 2007 Wiley Periodicals, Inc.