A unique interconnected porous Mn2O3/C@Co3O4 cubic composite, as efficient electro-active electrode for supercapacitors, was successfully synthesized via a facile two-step hydrothermal method. Novel cube-like Mn2O3/C@Co3O4 composite, with a high specific surface area (S BET) and conductivity, could promote charge transfer and improve the overall electrochemical performance. The as-prepared Mn2O3/C@Co3O4 composite exhibited the excellent reversible specific capacitance (523.8 F g−1 at a current density of 0.3 A g−1, much higher than Mn2O3/C), good rate performance (57.2% capacitance retention) and superior cycling stability (90.6% capacitance retention after 3000 cycles). In addition, an asymmetric supercapacitor (Mn-Co//AC) with Mn2O3/C@Co3O4 as the positive electrode and activated carbon (AC) as the negative electrode delivered a maximum energy density of 45.8 Wh kg−1 at a power density of 0.3 kW kg−1.