Background and Purpose : We were to investigate whether simple and electric acupuncture can affect the colonic transit time in both normal persons and chronic constipation patients. Methods: Twenty one volunteers were divided into two groups; first, normal control group(N=12) who had normal defecation habits, second, chronic constipation group(N=13). Before acupuncture, colonic transit time was checked using radio-opaque markers. Then simple acupuncture was done at four acupoints(both ST36, LI4) and maintained for 15 minutes during 4 days. Electric acupuncture was done using same methods except for applying 2Hz electrical stimulation. Result : In the normal group, after simple acupuncture, each transit time in the total, right, left was not changed statistic significance compared to pre-acupuncture(P>0.05), but which of rectosigmoid colon shortened statistic significance(P<0.05). After Electric acupuncture, transit time of right colon was shortened(P<0.05), and extended(P>0.05) in rectosigmoid colon compared to pre-acupuncture and simple acupuncture. In constipation group, after simple acupuncture, only rectosigmoid colonic transit time shortened statistic significance compared to pre-acupuncture(P<0.05). After electric acupuncture, also the transit time of rectosigmoid colon was shortened statistic significance compared to pre-acupuncture(P<0.05), but not to simple acupuncture(P>0.05). Conclusion : In normal persons without constipation, acupuncture affect the colonic transit time differently to the methods of it. In chronic constipation group, simple and electric acupuncture only reduces the rectosigmoid colonic transit time statistically significant(P<0.05).