Human lung carcinoma tissues with histological types of adenocarcinoma, squamous cell and small cell undifferentiated carcinomas were investigated for glycolipids. Carcinoma tissues, as well as normal adult and embryonic lungs contained ceramide mono-, di- and trihexosides, globoside and hematoside as major glycolipids. In addition to them, sulfatide which was identified as ceramide 3-sulfate-galactoside, was isolated in much lesser amount. The content of sulfatide was markedly increased in adenocarcinoma than that in other carcinomas and normal lung. Adenocarcinoma was also characterized by significantly lower level of total glycolipids which was largely due to the diminished contents of ceramide mono- and dihexosides, and hematoside, as compared to those in other two carcinomas. Squamous cell carcinoma had a characteristic pattern with an increment of hematoside. In small cell undifferentiated carcinoma, glycolipid contents were similar with those in squamous cell carcinoma but the relative composition of major glycolipids was markedly differed from that in other types. All the types of carcinoma examined showed marked increase of ceramide mono- and dihexosides (except for ceramide dihexoside in adenocarcinoma) compared to those in normal adult lung. Overall feature of glycolipids in embryonic lung appeared to be an intermediate between carcinomas and normal adult lung.