Acupuncture has been used as a clinical treatment in Oriental medicine for various diseases. In the present study was carried out to investigate the effects of acupuncture and electrical stimulation on the change neuronal nitric oxide synthase(nNOS) immunoreactive cells in the periaqueductal gray(PAG) area of the male SD rats. Enhanced expression of nNOS was detected in the dorsolateral-PAG(DL-PAG) area of rat with stress by fixed body, and acupuncture and needle electrode electrical stimulation groups at Hapgok like acupoint decreased the stress-induced enhancement in the expression of nNOS. The present results demonstrate that acupuncture and needle electrode electrical stimulation is effective in the modulation of expression of nNOS in the DL-PAG area under stress conditions.