The profile of hepatic lipids in rats fed an 8% casein diet supplemented with 0.3% methionine (BM group) was compared with that an 8% casein diet (B group) or a BM diet supplemented with 0.36% threonine (BMT group). 1) Hepatic triglyceride content of the BM group increased 2 to 4 times as much as that of the B group, but in the BMT group, it deceased to the lower level than that of the BM group. 2) No significant differences were observed in the net content and’ the relative concentration of phospholipid components of the liver between the B and BM groups. Feeding the rats on the BMT diet resulted in the increase in hepatic phospholipid content. 3) In the BM group, major fatty acid contents in hepatic triglyceride per unit weight of liver increased 2 to 3 times. Percentage of docosahexaenoic acid (to 3) in hepatic phosphatidylethanolamine tended to decrease on the third day or the seventh day after feeding with the BM diet. Furthermore, percentage of oleic acid in adipose tissue of the BM group decreased on the fourteenth day. 4) Total lipids of whole animal body including hepatic lipids tended to increase, but to a lesser extent, compared with those of the liver in the BM group. Judging from these results, it was suggested that the BM diet drastically affected not only the contents but also the composition of the lipids of the liver and the adipose tissue.