In this work, nanostructured polystyrene/polyaniline/reduced graphene oxide (PS-PANI/rGO) hybrid materials based on in situ reduction of graphene oxide with ascorbic acid and self-assembly have been successfully prepared for electrochemical supercapacitor and Na-ion battery applications. The supercapacitor based on the PS-PANI/rGO as an electrode material exhibits a specific capacitance of 180 F g(-1) at a current density of 0.5 A g(-1) from -0.4 to 1.0 V and a high energy density of 49 W h kg(-1) at the power density of 352.8 W kg(-1). Moreover, the nanostructured PS-PANI/rGO has a good cycle stability (74 % capacitance retention after 5000 cycles), indicating its future potential application in electrochemical energy storage. The material is further used as an anode in Na-ion batteries, and the results show that the porous nanostructured PS-PANI/rGO delivers a high capacity of 155 mA h g(-1) and keeps over 150 charge-discharge cycles at a constant current of 100 mA g(-1) (0.5 C).