Co-N-C electrocatalysts have attracted great attention in electrocatalytic ORR (oxygen reduction reaction) field. In this work, we propose to prepare Co2N nanoparticles embedded N-doped mesoporous carbon by a facile method including in situ copolymerization and pyrolysis under NH3 atmosphere. The results show that more N atoms can be doped in carbon framework by NH3 pyrolysis, it is also found that pyrolysis temperature and Co content can influence the ORR performance of samples. The sample prepared by adding Co precursor and pyrolysis at 700 degrees C has high N content (11.86 at%) and relative large specific surface area (362 m(2) g(-1)), and it also exhibited superior electrocatalytic ORR performance in terms of E-onset (- 0.038 V vs. SCE), E-1/2 (- 0.126 V vs. SCE) and large current density (5.22 mA cm(-2)). Additionally, the sample also shows better stability and resistance to methanol poisoning than Pt/C catalyst. The synergistic effect of Co-N active centers and hierarchical porous structures contribute the excellent electrocatalytic activity, which are considering as alternative catalysts for ORR in full cells.