Nanoscaled crosslinked poly(vinyl alcohol) PVA fibers were prepared by electrospinning. This study described its electrospinning process, structure, and filtration applications. The fibers were found to be efficiently crosslinked by maleic acid. Vitriolic acid was used as a catalyst activator during crosslinking. Scanning electron micrograph and differential scanning calorimetric techniques as well as infrared reflection-absorption spectroscopy (FTIR) were employed to characterize the morphology and structure of crosslinking of PVA fibers, PVA fibers as well as PVA powder. Moreover, the filtration properties of crosslinked PVA nanofibers were tested. During the experiments, crosslinked PVA nanofibers layers with different area weight were placed on the spunbond or meltblown sublayers. The result shows that the filtration efficiency increases sharply when crosslinked PVA nanofibers layers were added to the sublayers. (C) 2008 Wiley Periodicals, Inc.