In this study, the analytical expressions for the hydraulic permeability and Kozeny–Carman(KC) constant of porous nanofibers are derived based on fractal theory. In the present approach,the permeability is explicitly related to the porosity and the area fractal dimensions of porousnanofibers. The proposed fractal models for KC constant is also found to be a function ofthe microstructural parameters (porosity, area fractal dimensions). Besides, the present modelclearly indicates that KC constant is not a constant and increases with porosity. However, KCconstant is close to a constant value which is 18 for φ > 0.8. Every parameter of the proposedformulas of calculating permeability and KC constant has clear physical meaning. The modelpredictions are compared with the existing experimental data, and fair agreement between themodel predictions and experimental data is found for different porosities.Keywords: Fractal; Porous Nanofibers; Permeability; Kozeny–Carman Constant.