Synthetic processes of organic resorcinol/formaldehyde(RF) aerogel and RF-polystyrene(PS) composite aerogel were proposed based on sol-gel processing technique. Also, by synthesizing TMOS-aniline composite aerogel, the potential utility of aerogel for conducting materials was conformed. RF aerogel obtained by supercritical fluid drying was found to retain low density, high porosity and specific surface properties. However, it shows intrinsic structural fragility against impact. To improve such a drawback with the RF aerogel, a new organic composite RF aerogel with polystyrene(RF/PS) was also made. In synthesizing the RF/PS aerogel, RF solution was impregnated into PS foam, which was obtained by an emulsion polymerization. Then the RF/PS wet gel was cured and residual liquid in the internal pores of the gel was removed by a conventional drying. In contrast to the RF aerogel, we found that the RF/PS aerogel showed relatively lower homogeneties in its porosity, pore sizes and pore structures than the RF. However, it showed significantly the enhanced mechanical strength and the improved machining aspect. Furthermore the overall process of obtaining RF/PS was simpler than the case of RF aerogel. We also found that the average size of pores of the RF/PS depended on the conditions of the polymerization. Also, the morphology and stability of the PS foam was controllable by the amount of changing emulsifying agent, the reaction temperature and stirring rate.