Objective To assess the dlagnostic value of a triple stimulation technique(TST)for benign monomelic amyotrophy(BMA). Methods A total of 15 BMA patients and 15 healthy control subiects were exam-ined with the TST.The latent periods,amplitudes,areas and durations of the negative waves of the compound muscle action potential(CMAP)and motor evoked potential(MEP)induced by the stimulation were recorded,and the de-creasing ratio of amplitudes and areas in the two groups were analyzed. Results There were significant differences in amplitude and area ratios between the BMA patients and the healthy control subjects.Both ratios were significantly lower in the BMA patients. Conclusion TST has some value in diagnosis of BMA.