Electrospinning performance of 5-52 wt% perfluorosulfonic acid (PFSA), poly (N-vinylpyrrolidone) (PVP), and PFSA/PVP blends in N,N-dimethylformamide (DMF) with various PFSA/PVP ratios were systematically investigated in respective of solutions properties, mainly surface tension and rheological properties. Mechanical relaxation time tau(M) calculated from rheological results happens to be closely correlated with nanofiber morphology, and is used to evaluate the electrospinnability. Polymer solutions with higher tau(M) show better electrospinnability. Morphologies of the electrospun samples were observed by Scanning electronic microscopy. The results show that the pure PFSA solutions, even with a quite high concentration up to 52 wt%, fail to be electrospun and possess a very low tau(M). Addition of PVP improves electrospinnability of PFSA and increases tau(M). The electrospinnability of PFSA/PVP/DMF solutions can be manipulated by changing the ratio of PFSA to PVP and the total polymer concentration of the mixed solutions. The PFSA nanofiber mats with a small fraction of PVP (<8 wt%) with the average diameter of 370 nm were successfully obtained.