[en] Highlights: • Novel porous PANI modified MWNTs core-shell material (porous CNTs-PANI) was fabricated. • The porous CNTs-PANI possesses an excellent specific capacitance of 406.5 F/g at 0.5 A/g. • It exhibits good rate capability of 84.7% even up to 50 A/g. • It exhibits a high energy density of 55.6 Wh/kg at the power density of 0.25 kW/kg. Novel porous polyaniline (PANI) modified MWNTs core-shell structure materials (porous CNTs-PANI) were fabricated by in situ polymerization using the “worm-like” MnO₂ modified MWNTs (CNTs-MnO₂) as the reactive template. The MnO₂ layer on surface of MWNTs can act as the reactive template in the polymerization process. Meanwhile, the reactive etching of the MnO₂ can form porous structure of PANI for fabrication of porous CNTs-PANI core-shell structure, which exhibits outstanding electrochemical performance among the CNTs-PANI and pure PANI materials. The porous CNTs-PANI materials possess an excellent specific capacitance of 406.5 F/g at 0.5 A/g, exhibit good rate capability of 84.7% even up to 50 A/g, and keep 72% of its original value up to 1000 charge-discharge cycles at the current density of 10 A/g, also maintain 55% capacitance retention at 2200 charge-discharge cycles. Furthermore, the porous CNTs-PANI materials exhibit an extremely high energy density of 55.6 Wh/kg at the power density of 0.25 kW/kg. The novel porous CNTs-PANI core-shell structure materials reveal promising applications in high performance supercapacitors.