Sal. typhi, Sal. paratyphi A and Sal. paratyphi B which are the representative strains of group D, A snd B of Salmonella group respectively, have special characteristics of inducing typhoid fever in man. Their complex antigenic structures and biochemical characters are already well known. The authors studied the difference, if any, in the lipid components among these strains, while comparing with the lipid components of other Enterobacteria. 1. The major components of phospholipid were found to be identical in all the three strains. Moreover, these were almost the same in E. coli and Sal. typhimurium, with an exception of a minor unknown component in E. coli. 2. Considering the composition of individual components, three strains contained a considerable amount of cardiolipin (10-13% of total phospholipid). On the other hand, they contained phosphatidyl glycerol in several to 10% . 3. Among the three strains, Sal. paratyphi B tended to show the quautities of cardiolipin and phosphatidyl glycerol very similar to those in E. coli B. 4. The fatty acid composition of total lipids in these three strains did not differ so appreciably from that of E. coli. Main components of the fatty acid were palmitic, palmitoleic and oleic acids.