Composition and content of ceramides and gangliosides from different kinds of human ovary benign and malignant epithelial tumours were studied. The ceramide content was shown to decrease significantly in the tumours, especially in malignant tumours, in comparison with the normal ovary tissue. In the tumour ceramides a sphingosine base composition changes: sphinganine was found along with sphingenine, which is characteristic for normal ceramides. The fatty acid composition changes also. Main tumour gangliosides were shown to be GM3 and GD3. Their content decreases in malignant ovary tumours, especially the amount of ganglioside GD3. As a result of these changes the molar ratio Cer/Sia decreases. It can appears stimulates a tumour growth.