Defect and N-activated electronic engineering are of paramount importance for developing highly active carbonbased electrocatalysts toward oxygen reduction reaction (ORR) because the binding affinity of the carbon matrix can be efficiently tuned and thus promote the electrocatalytic activity. Herein, we present a facile and general strategy for fabricating pyridinic-N dominated and defect-enriched graphene-like nanocarbon material (NDGLC) involving in-situ alkaline activation of cellulose and ammonia injection. The ND-GLC material has a superior and enhanced ORR activity and stability compared to commercial Pt/C catalyst in both rotating disk electrode measurements and Zn-air battery applications. Experimental and theoretical studies describe that the high electrocatalytic activity of ND-GLC mainly originates from the synergetic effect of edges/defects and pyridinic-N dopants. Importantly, our concept is demonstrated to be universal for other carbon-based nanomaterials (i.e., graphite nanoplates, carbon nanotubes, carbon nanospheres, graphene nanosheets).