We have investigated the electronic transport of graphene nanoribbons (GNRs) with armchair edges containing boron, nitrogen, or oxygen, using the first-principles density functional theory. We found that such dopants at edge sites provided the n- or p-type doping effect for armchair graphene nanoribbons (AGNRs). As a result, even under an applied bias potential lower than the band gap energy of pristine AGNR, the nitrogen edge-doped GNRs show a large conductance that is almost the same as that of the ideal zigzag GNRs.