In healthy persons with normal salivary glands, authors studied excretory function of salivary glands radiologically after injection with 40% lipiodol into the Wharton's duct (35 cases) and the Stensen's duct (37 cases) respectively. The results of this study were as follows : 1) The injected contrast material in the submaxillary gland rapidly disppeared rather than that of the parotid gland in 2 hours observation. 2) In 12 cases (34.29%) the injected contrast material in the submaxillary gland disappeared within 1 hour, and one case in the parotid gland disappeared within 2 hours. 3) The injected contrast material in branched duct of the submaxillary gland disappeared within 1 hour in all cases except one, most of the cases in branched duct of the parotid gland disappeared within 2 hours (89.19%). 4) The injected contrast material in the Wharton's duct disappeared within 1 hour in 17 cases (77.14%), but the materials in the Stensen's duct did not disappear within 2 hours in all cases except one. 5) The wider the diameter of main duct, the more rapid disappearance of injected contrast material in main duct and branched duct. 6) In most cases, the injected contrast material of branched duct disappeared at first, then in main duct and last in the gland.