The wild type and two morphological variants of Streptomyces viridochromogenes were studied for their lipidand fatty acid compositions at different incubation temperatures. It showed that a decrease in triacylglycerol content was closely linked to the aerial mycelium formation. Phospholipids showed no characteristic changes, except that the contents of phosphatidylethanolamine were clearly high for aerial mycelium deficient strain BR2 grown at $20^{circ}C$. The strain BR2 also presented unidentified aminolipids with various $R_{f}$ values. Among the aminolipids, ornithinolipid increased gradually during the cultivation for all strains. The changes in fatty acid compositions showed a temperature dependency that the proportion of unsaturated acids decreased as the growth temperature increased. The proportion of straight chain saturated fatty acids decreased as the aerial mycelium developed, and it was most evident for the mutant strain M13 with more extensive aerial mycelium. The mutant strain BR2 presented significantly higher level of iso branched odd numbered saturated fatty acids.