The Co-N-C catalyst with higher nitrogen content was fabricated with a polymerizable ionic liquid (PIL) of hydrolyzed vinyl imidazolium dihydrogen phosphate ([HVim]H2PO4) as N-doping precursor. The PIL was first prepared and then reacted with Co(NO3)(2)center dot 6H(2)O. The N-doped Co-based catalyst was then obtained after carbonization process at 600 degrees C. The electrochemical characterization indicated that the electroactivity of catalyst prepared with PIL shows higher activity toward oxygen reduction reaction (ORR) than that of the sample prepared with non-IL precursor or nonpolymerizable IL under similar conditions. The ORR onset potential of the Cl (Pm as precursor) was approximately 100 mV higher than the counterpart prepared with C-2 (non-IL precursor) or C-3 (nonpolymerizable IL precursor) in basic electrolyte. The XPS results demonstrated that C-1 contains higher nitrogen with more pyridinic and pyrrolic nitrogen groups, which was favorable for ORR.