The cause of the target fade-out and the ghosting artifact in NN nonuniformity correction scheme for infrared focal plane array(IRFPA) was studied.It was found that ignoring target edge and updating correction coefficients blindly in the NN-NUC scheme were the cause of the problems.Based on this consideration,an edge-directed NN-NUC scheme(ED-NN-NUC) was proposed to eliminate the ghosting artifact and the target fade-out.The comparison experiment with simulated data and real IRFPA infrared data shows that our viewpoint is correct,and the proposed scheme is effective.