Glycolipid compositions of the human glioma cell lineT98G were studied during each phase of thecell cycle to see if those cell surfacemolecules are concerned with cell proliferation. In vitrocultured non-synchronized T98G cells are composed of ceramidemonohexoside(CMH), ceramidedihexoside (CDH), ceramidetrihexoside (CTH) and neolactotetraosylceramide (nLc4Cer)as neutral glycolipids, and of sulfatide (CS), gangliosidesGM3, GM2, GD1a and several other gangliosides asacidic ones. While total glycolipid content per cellularweight was shown to be increased during theM phase, deletion of complex gangliosides particularly b-seriesgangliosides was recognized (p < 0.05). The glycolipidprofile in other phases was fairly consistent, andthere was no glycolipid molecule specific to acertain phase of the cell cycle. Relative enhancementof simple gangliosides with a decrease of complexones during mitotic division may imply the functionalinvolvement of complex gangliosides in cell-cell or cell-matrixattachment, which may have to be abandoned duringthe process of detachment from the matrix orcellular cleavage.