Hybrid mesoporous polystyrene-silica materials were successfully prepared through HCl-catalyzed sol-gelreactions of tetraethyl orthosilicate (TEOS) and triethoxysilyl-functionalized polystyrene obtained via atom transfer radicalpolymerization (ATRP) of styrene, in the presence of citric acid (CA) as non-surfactant template or pore-forming agent andfollowed by ethanol extraction to remove template molecules. The materials were characterized by infrared spectroscopy(IR), N_2 adsorption-desorption measurements, powder X-ray diffraction (XRD), thermogravimetric analysis (TGA) andtransmission electron microscopy (TEM). The results indicate that the materials prepared with 50 wt%-60 wt% templatecontents have average pore sizes of 2-3 nm and large surface areas (ca. 886 m~2/g) as well as high pore volumes (ca.0.53 cm~3/g). The mesoporosity arises from interconnected channels and pores with disordered arrangements. The porediameters and pore volumes increase as the template content is increased. The pore diameters show a little change uponheating at 200℃ overnight. However, the materials do not have good hydrothermal stability. Hybrid mesoporous polystyrene-silica materials were successfully prepared via HCl-catalyzed sol-gel reactions of tetraethyl orthosilicate (TEOS) and triethoxysilyl-functionalized capsules obtained via atom transfer radical polymerization (ATRP) of styrene, in the presence of citric acid (CA) as non- surfactant template or pore-forming agent and followed by ethanol extraction to remove template molecules. The materials were characterized by infrared spectroscopy (IR), N2 adsorption-desorption measurements, powder X-ray diffraction (XRD), thermogravimetric analysis (TGA) and transmission electron microscopy (TEM). The results indicate that the materials prepared with 50 wt% -60 wt% templatecontents have average pore sizes of 2-3 nm and large surface areas (ca. 886 m ~ 2 / g) as well as high pore volumes The mesoporosity arises from interconnected channels and pores with disordered arrangements. The poredia meters and pore volumes increase as the template content is increase d. The pore diameters show a little change upon heating at 200 ° C overnight. However, the materials do not have good hydrothermal stability.