In this study, we report a simple approach based on the complexation of water soluble polymer with metal cations, for fabricating well defined polypyrrole (PPy)/ ionic liquid (IL) nanoparticles (24-44 nm in diameter) by chemical oxidation polymerization. This procedure doesn't require harsh environment such as temperature and pressure and the simple process offers a great possibility for mass production of polymer nanoparticles. The obtained PPy/ IL nanoparticles were tested as an electrocatalyst for oxygen evolution reaction. We have not added any transition metal or metal oxide. But, the as-prepared catalyst has ionic liquid which containing 1-allyl-3-methylpyridinium cation and tetrachloronickelate anion complex. The as-prepared catalyst PPy/ IL nanoparticles showed the Tafel slope of 53mVdec(-1). High catalytic activity of PPy/ IL for OER is evident from low onset potential of 516mV (.1= 328mV) and high current density observed in the polarization curve. Moreover, the as-prepared catalyst achieved current density of 10mA cm(-2) at low potential of only 583mV which corresponds to an overpotential of only 392mV.