The aim of this study is to develop the templateless fabrication of hierarchical porous carbon nanofiber (CNF)/MnO2 composites (PMnCD) derived from polyacrylonitrile (PAN)/cyclodextrin (CD) and investigate their morphological and electrochemical properties to determine the different capabilities of inclusion complexes (ICs) formed by α-CD, β-CD and γ-CD. Among the three CD phases, the PMnCD(β) composite using β-CD exhibits a hierarchical porous structure with large specific surface area of 499 m2g-1, and total pore volume of 0.32 cm3g-1, which helps with adsorption efficiency and accumulation of hydrated molecules for double-layer formation. In addition, the numerous mesopores and nitrogen functionalities of the PMnCD(β) composite provide fast diffusion channels for electrolyte ions and higher attractive interactions with electrolyte ions through the pseudocapacitive character. As a result, the PMnCD(β) electrode has a high specific capacitance of 228 Fg-1 at 1 mAcm−2, maximum energy density of 25.3–16.0 Whkg−1 in the power density range of 400-10,000 Wkg-1, and excellent cycling stability of more than 94% after 10000 cycles in aqueous solution, thereby offering potential applications for supercapacitors. Display omitted •Hierarchical porous PMnCD is fabricated by electrospinning without a template.•β-CD stabilizes and encapsulates MnCl2 through the good size match of β-CD and MnCl2.•PMnCD(β) shows a large specific surface area for accumulation of ions.•Many mesopores and nitrogen groups of PMnCD(β) provide fast ion diffusion.•Hierarchical porous PMnCD(β) is applied to high-performance supercapacitors.