Abstract: A kind of glass therapy microsphere of 90Y has been developed for use as a therapeutic agent of the hepatic rumor delivered via intro-hepatic artery catheter. The glass microspheres of 30 - 50 microns in diameter can be activated by neutron bombondment to obtain 90Y glass therapy microspheres (GTMS). The activated GTMS is analysized using Beckman LS7500 liquid scintillation spectrometry and Ge(Li) γ-ray spectrometry. The 90Y-GTMS solubilizing rate in saline solution is about in the order of 10-5. The tissue distribution results demonstrate that no detectable activity is found in spleen.stomach,colonileum bone,bone marrow except in gallbladder bile duct and pancreas. Distribution within the liver is complete.Clinical investigation is now being carried out in order to improve the technique of administration and to solve the problems which still remain unopen. Remission of the tumour has been especially satisfactory in almost all of the 20 cases treated.