A microorganism, isolated from soil and designated Pseudomonas sp13, produced two kinds of rhamnolipid in the medium containing glucose as carbon source. There were both rhamnolipid contain L-rhamnose and ${eta}$-hydroxydecanoic acid. Coumpound A and B elucted chloroform-methanol mixed solution of silicic acid column chromatography and recrystallized from a mixture of ether and n-hexane. Studies on the structure of these products reveled that compound A is L-rhamnopyranosyl-${eta}$-hydroxydecanoyl-${eta}$-hydroxydecanoic acid and compound B is L-rhamnopyranosyl-L-rhamnopyranosyl-${eta}$-hydroxydecanoyl-${eta}$-hydroxydecanoic acid.