The effecs on digestion and absorption produced by a radical operation of stomach cancer with complete removal of the regional lymphnodes, studied by means of the patients subjected to the same operation, whose digestion and absorption was tested by Cr O ratio method. At the same time, for comparison, the same test was performed on patients subjected to simple gastrectomy and healthy men, with the following conclusion. 1. In patients after simple gastrectomy, absorption of fat and protein goes not so well as in healthy persons. 2. In patients after airadical operation of stomach cancer with complete removal of the regional lymphnodes, absorption of fat and protein is well performed as in patients after simple gastrectomy. 3. In patients after redical operation of stomach cancer and in those after simple gastrectomy, absorption of carbohydrate is carried on with almost the same rate, i. e. more than 99%, as in healthy persons.