In this study, polyaniline (PANI)/WO3 electrode was prepared as an anode of a lithium ion capacitor, and its electrochemical characteristics were measured and analyzed. When PANI was electrochemically deposited on the surface of WO3 electrode, the capacity of PANI/WO3 was improved with increase of the deposited amounts of PANI. Furthermore, the effect of light irradiation on capacity and coulombic efficiency was examined by irradiating sunlight during charging and discharging. When the light was irradiated to the WO3 electrode and the PANI/WO3 electrode, those capacities and coulombic efficiencies were increased compared to that measured under the dark condition. It is attributed to the photocatalytic property of WO3 that can generate photoelectrons by light irradiation. In PANI/WO3 electrode, PANI also can be excited under the light irradiation with affecting the electrochemical property of electrode. The photoelectrons improve the capacity by participating in the intercalation of Li+ ions, and also improve the coulombic efficiency by facilitating electrons’ transport. Under the dark condition, the capacity of PANI/WO3 was gradually reduced with increase of cycles due to a poor stability of PANI. However, the stability of PANI was significantly improved by the light irradiation, which is attributed to the oxidation-reduction reaction originated from the photogenerated electrons and holes in PANI/WO3.