Recently we made the electromyographic study on human gastrointestinal tract using the endoscopic method is useful for the clinical studies of the patho-physiological aspects on human gastrointestinal tract. The silver bipolar needle electrode which was 0.2 mm in diameter, 10 mm in length and 1.0 mm in interpolar distance and the electroencephalography recorder provided with pen-writer were used for this research. The endoscopy was done to the volunteer anesthetized his pharynx with xylocaine spray. 20 cases of gastro-electromyograms, 35 cases of duodeno-electromyograms and 5 cases of the electromyograms of duodenal papilla were recorded. On these endoscopic electromygorams, the typical rhythms and patterns of electrical activities were disturbed by various kinds of factors; that is, on the endoscopic manipulation, the sticking of needle electrode into the shallow layer of gastrointestinal wall and automatical pouring of water into canal through the endoscope. On volunteers' condition, his deep breathing, electrocardiogram and vasotonic condition were important factors. Typical duodeno-electromyograms showed the grouped spikes synchronizing with the duodenal peristalsis observed endoscopically. The electromyograms of the duodenal papilla showed the similar patterns and rhythms to those of duodeno-electromyograms on active phase. In the clinical study on the correlation and propagation between gastric and duodenal motility, the rhythms of electrical activities on duodeno-electromyograms were not similar to the rhythms of gastric peristalsis at the prepyloric region. The propagation of gastric movement to duodenal bulb were not able to be clarified. We assumed that the gastric and duodenal motility occurred each other on the different rhythms.