Cell surface carbohydrates serve as differentiation and developmental markers characteristic of different cell and tissue types. Expression of these carbohydrate antigens is often significantly altered in tumors particularly in those arising from epithelial tissues. Analysis of the expression of cell surface carbohydrates in normal endometrium has shown that this glycosylation is hormonally influenced. Change in expression of carbohydrates in malignant tissue should therefore be evaluated against this normal fluctuation. In normal cervical uterine epithelium the result shows that the glycosylation of metaplastic squamous cells is different from that of original squamous cells indicating that the regulation and differentiation of the epithelium in the transformation zone is different from that of the original squamous epithelium. This variation in expression of carbohydrates seen in the metaplastic epithelium may be of importance for the development of carcinomas in this area.