The ultrafine poly (sodium 4-styrenesulfonate) (NaPSS) fibres have been prepared for the first time by electrospinning. The spinning solutions (NaPSS aqueous solutions) in varied concentrations were studied for electrospinning into ultrafine fibres. The results indicated that the smooth fibre could be formed when the concentration of NaPSS was above 40 wt.%. The morphology of the fibres was shown by scanning electron microscope (SEM). The Fourier transform infrared spectroscopy (FTIR) indicated that the structure of NaPSS did not change after electrospinning.