Histologic observation was made on the lesions in the salivary glands and pancreas of the mouse and rabbit caused by hydrogen sulfide poisoning. From the data obtained the present author concluded that the poisoning causes definite histologic changes in these tissues as follows: 1. In the parotid glands, the gland cells show a marked atrophy with a tendency of close arrangement of secretion glanules in the cytoplasm, and with a vacuolar degeneration or appearance of basement membrane. Moreover, the epithelium of the striated tubules decreases its height. 2. In the submaxillar salivary glands, the gland cells as well as the epithelial cells of the striated tubules show a high degree of atrophy with a marked decrease of secretion glanules. Vacuolar or collagenous degeneration is also seen in the gland cells. 3. In the pancreas, the acinar cells are degenerated with a marked decrease of zymogen granules and a vacuolar degeneration in the cytoplasm, resulting in a appearance of the basement membrane. Islets of Langerhans increase their sizes with the remarkable increase in number of beta cells and the slight increase of alpha cells. These changes show that the hydrogen sulfide poisoning causes a marked decline and disturbance of excretory function in the salivary glands and pancreas. According to the methods used in the poisoning, there is no difference in quality of the changes, but more or less difference in their intensity, the higher degree of changes are caused by injection than by inhalation and intragastric introduction of hydrogen sulfide.