Of three groups of cows affected with fat necrosis (FN) in the field group 1 was administered with a daily dose of 300 g of the adlay, Coix Lachryma-jobi, group 2 with a daily dose of 150 g of substance S from soybeans containing vitamine E, and group 3 with a combination of a daily dose of 150 g of the adlay and the same dose of substance S for about 4 consecutive months. One-half of the cows of each group was loaded intravenously with arginine attempting at reducing the period of treatment. The disapperance rate of necrotic fat masses was 17%, and the reduction in size of these masses was evident in 67% of treated animals from the results of rectal palpation. In the affected cows the amount of secretion of glucagon in response to the loading with arginine, decreased while the glucagon level after treatment was essentially the same as in the healthy ones. The free fatty acid level in the affected cows exhibited an abnormal pattern of secretion before and after treatment as compared with that in the healthy ones. The results suggested a disordered endocrine function of the pancreas in FN affected cows.