The dye scattering method is one of useful methods to observe gastric mucosa in detail endoscopically. In reading the endoscopical picture with dye scattering method, it is necessary to know the characteristics and the effects of this method. In order to investigate the difference in endoscopic view between dye scattering method and normal method, the dye scattering method was performed in 252 cases. 1) The dye scattering method is more effective to recognize the existence of ulcerous changes in the stcnmach. 2) It is easy to decide the stage of gastric ulcer correctly using this method, 3) The merit of this method is not only to observe the minute appearance of gastric mucosa easily, but also to recognize the existence and the extent of redness clearly.4) Comparing the dye scattering method with normal method, the effects of this method are investigated statistically by means of giving points depend upon the degree of clearness of endoscopic findings. i) Without distinction of stages and findings, endoscopic view with this method are more clear than that with normal method. ii) The degree of the effects of this method vary in strength according to findings. Six findings and the order are as follows. fine relief <conversing folds, appearance of whitish coat, surrounding redness, surrounding edema<existence of whitish coat iii) It is also the same conclusion as i) among four findings which are necessary to decide the stage of ulcer, (whitish coat, edema, redness and conversing folds). As described above, the dye scattering method is the excellent and effective one to observe the gastric ulcer in detail endoscopically. With this method the endoscopical diagnosis of gastic ulcer becomes to be accurate, it is valuable especially in distinguishing early gastric cancer from benign ulcer. This method is not difficult and does not take long time to perform, so this method should become the routine of particular-endoscopy on gastric ulcer.