The development of novel high-performance electrode materials has become increasingly urgent due to the broad demands on the large-capacity energy storage devices nowadays. In this work, cagelike porous sulfonated polystyrene (cSPS) microspheres are first synthesized as the skeleton structure templates, on which polyaniline (PANI) nanoparticles with a size of about 30 nm are loaded through the in situ polymerization of aniline. The novel cSPS-supported PANI composite microspheres (cSPS@PANI) possess hierarchical meso-/macroporous structure, and their BET specific surface area and pore volume reach the maximum at a moderate PANI mass fraction. The electrochemical performance of cSPS@PANI composite microspheres was evaluated through a three-electrode system with 1 M H2SO4 as the electrolyte. The specific capacitance of the cSPS@PANI composite microspheres can reach as high as 374 F g(-1) at a current density of 1 A g(-1), and only 11.8% is lost after 500 charge/discharge cycles. Thus, the cSPS@PANI composite microspheres can be potentially used as one of the novel outstanding electrode materials in the fabrication of high-performance energy storage devices.