Combinational approaches of rare earth oxides with conducting polymer composites have gained vast attention in supercapacitor field due to the outstanding pseudocapacitive property. Here we detail the redox reaction based on CeO2/polyaniline nanostructure to grasp the superior electrochemical nature of the composite. The CeO2/polymer nanostructure showed the improved specific capacitance of 1452 F g(-1) at 2A g(-1) when compared to pristine CeO2 (927 F g(-1) at 2A g(-1)). The composite also maintains excellent rate capacitance (875 F g(-1) at 10 A g(-1)) and good cyclic stability upto 1500 cycles at high current density of 20 A g(-1). Symmetric and asymmetric supercapacitor devices were fabricated using CeO2/PANI as an electrode. Moreover, the asymmetric supercapacitor possesses excellent specific capacity (256 F g(-1) at 2 mV s(-1)) with high energy density (75 Whkg(-1)) and high power density (566 Wkg(-1)). These results suggest a potential usefulness of CeO2/PANI composite exploit as an efficient electrode for supercapacitor applications.