Transaminases GOT, GPT) purified partially from the dog liver were seperately injected into the vein of normal dogs. Following the injection the engyme levels in the blood and bile were measured. 1. The disappearance of the exogenous serum GOT was more rapid than that of GPT after the administration, and the half-life of GOT in the circulation was estimated to be approximately 6 hours. 2. In the lymphatic fluid the activities of the exogenous GOT and GPT increased immediately after the injection and reached to the similar levels with the serum activities 7 hours after the injection, then both activities decreased in a parallel manner, showing a little higher levels in the lymphatic fluid than those in the bile. 3. In the bile the activities of GOT and GPT elevated very slightly following the injection and GOT appered to be excreated more easily than GPT.