The examination of 46 patients with peptic ulcer of a bulb of a duodenal intestine (PUBDI) and 30 healthy people has been conducted. The ozonized physiological solution was injected to the patients with PUBDI intravenously. The ozonized distilled water was taken by the patients perorally. The healthy people took only ozonized distilled water. The research of the secretory function of a stomach was conducted by the method of inside – gastric pH-measuring. It is ascertained