A novel nanocomposite of polyaniline/urchin-like mesoporous TiO2 spheres (PANI/UMTS) has been synthesized as electrode material for supercapacitors. In the composite, UMTS are used as support material and modified by γ-aminopropyltriethoxysilane (APTES), PANI is assembled onto the surface of it via grafting polymerization. Characterization of structure and morphology of the composite indicates that the UMTS with good mechanical strength and high specific surface area can improve the morphology of PANI and increase its stability. Consequently, PANI/UMTS exhibits excellent electrochemical performance. A high specific capacitance of 422Fg−1 is reached at a current density of 0.7Ag−1, and a high capacitance retention ratio of 73% as the current density is increased by 20 times can be achieved. In addition, almost 100% of its initial specific capacitance can be retained after charge/discharge for 500 cycles. All results suggest that the PANI/UMTS is a promising electrode material for high-performance supercapacitors.