By comparing gastric cancer tissues treated by the conventional hematoxylin and eosin (HE) staining and those by the chemical staining of immunohistologicals using monoclonal antibodies (MoAB) which recognize different carbohydrate antigens, the relation of cancer tissue patterns between the two staining methods was studied. Consequently, stainability was not seen in MoAB-FH4, AH6, FH6 and TKH2 in the cancer tissues where MoAB-SH1 responded to immunohistological staining. Likewise, each of MoAB-FH4, AH6, FH6 was found to have its own stain localization. The patterns made by immunohistological staining using MoAB showed so-called mosaicism even where the HE stain presented the same histologic form. Study of correlation between gastric cancer patterns and MoAB's localization revealed that localization of MoAB-SH1, AH6 and TKH2 was predominant in well differentiated adenocarcinoma. On the contrary, MoAB-FH4 and FH6, which are more specific, showed predominant localization in poorly differentiated adenocarcinoma of gastric cancers. Localization of MoAB-FH6 and AH6 increased as cancer grew from the early stage to the advanced stage. These results leads to this assumption: cancer, being of an isogenic carbohydrate structure at the initial stage when carcinoma in situ is generated, gains heterogeneity with the process of growth, differentiating into various directions and thus changing into a complicated carbohydrate structure.