Carcinoembryonic antigen (CEA)was measured with ABC immunohistochemistry method in fourty-one gastric cancer tissues and sixty-six tissue from normal stomach and gastric benign lesions. The study revealed that the reactive signals in the former were ber than those in the latter. Simultaneously, CEA localized mainly in the cytoplasm or stroma in the cancerous tissue, but in normal gastric tissue or benign gastric lession, CEA distributed mainly in the margin of gland with gastric depression or membranous type. The result also revealed that the distribution patterns of ECA were linked with the cell growth types and infiltrating of gastric cancer. The authors consider that the expression state of CEA in gastric cancer is correlated with its biological behavior, and distribution patterns of CEA are more clinically significant than reactive intensities in the tissue. Patients have different prognosis with different CEA distribution patterns in tissue though their pathological types and TNM stages are the same.