TCD(transcranial doppler, TCD) units is a equipment that measure a blood flow velocity in the middle cerebral artery(MCA), anterior cerebral artery (AC A), posterior cerebral artery (PC A), and vertebral artery(VA). The aim of this study was to determine the influence on cerebral blood flow velocity according to different stimulation frequency of interferential currents. 50 patients who has a cervical pain were participated in this study and randomly divided into one of the three experimental, placebo, and control group: (l)IFS 1； 10~30Hz was applied, (2)IFS 2； 30 ~ 50Hz was applied, (3)IFS 3； 50~100Hz was applied, (4)placebo； suction only applied, and (5)control； neither suction nor interferential stimulation applied. In the. IFS groups, interferential stimulations were applied through four suction electrodes application from the 5th cervical to the 1st thoracic level. The results were as follow； MCA was statistically significant with IFS 1, IFS 2, IFS 3, and Placebo group(p< 0.05), But there was no statistical significance between IFS 1 and IFS 3 group(p >0.05). ACA was statistically significant with IFS 1, IFS 2, and IFS 3 group(p<0.05). And IFS 1 was more statistical significance than IFS 3 group on ACA(p<0.05). PCA was statistically significant with IFS 1, IFS 2, and IFS 3 group(p<0.05). And IFS 1 was more statistical significance than IFS 3 group on PCA(p<0.05). VA was statistically significant with IFS 1, IFS 2, and IFS 3 group(p<0.05). And IFS 1 was more statistical significance than IFS 3 group on VA(p<0.05).