The absorption of medium chain triglyceride (MCT) has been investigated with intestinal loop of dog without both bile and pancreatic juce. On optimal state, the average coefficient of fat absorption was 78.1±7.4%. The use of medium chain triglyceride diet for 4 weeks in dogs had some effecton lipids of serum and adipose tissue but minimal change on clinical evidence was found. There was a prompt reduction in the proportion of arachidonic acid and a sustained increase in the proportion of oleic acid and linoleic acid in serum lipid. Analysis on lipids of adipose tissue showed prompt reduction in the proportion of oleic acid and linoleic acid. Neither clinical evidence nor side effect induced with medium chain triglyceride was found.