This study focused on the fabrication and characterization of ammonium metatungstate hydrate (AMT) combined with cobalt(III) acetylacetonate (Co(acac))-loaded electrospun micro-nanofibers. The morphologies, structures, element distribution, through-pore size, and through-pore size distribution of AMT/Co(acac)-loaded PAN/PS micro-nanofibers were investigated by a combination of field emission scanning electron microscopy (FESEM), flourier transformation infrared (FTIR) spectroscopy, energy disperse spectroscopy (EDS), through-pore size analyzer, and so on. These micro-nanofibers have many advantages in their potential application as electro-catalysts. The porous and large thorough-pore will benefit for effective electrolyte penetration, in addition to promoting gas bubbles evolving and releasing from catalyst surface timely.