AbstractGangliosides extracted from human placenta were composed of four major components (G1–G4), which were purified by silica beads column chromatography. The structures of these gangliosides were analyzed by exoglycosidase treatments, 400 MHz proton magnetic resonance spectroscopy and gas chromatography‐mass spectrometry and were concluded to be as follows: image Gangliosides containing more than 10 sugar residues were observed in addition to the above four major components. But ganglio‐series gngliosides were undetectable in the placenta.