Abstract: Objective 　To study the expression of β-galactoside-binding protein-3 in gast ric cancerous tissues and the relationship between β-galactoside-binding protein-3 expression and biological behavior in gastric carcinoma. Methods 　Immunohistochemistry method of S-P was used to examine β-galactoside-binding protein-3 expression in 64 primary gast ric cancerous tissues. We examined the expression of β-galactoside-binding protein-3 by HPIAS-2000 Image analysis sof tware. Results 　Positive β-galactoside-binding protein-3 expression was observed in 85. 9 % of the gast ric cancer cases. In gast ric cancerous tissues, 46 % of cases showed st rong nuclear immunoreactivity. The degree of enhancement of immunoreactivity was different corresponding to various histopathological subtypes in cancerous tissues. The average absorbency of β-galactoside-binding protein-3 in well 、moderate and Poorly differentiated adenocarcinoma tissues was 0. 1713 ±0. 02147 、0. 1873 ±0. 0313 and 0. 2538 ±0. 1216 respectively. A significantly stronger expression of β-galactoside-binding protein-3 in cancerous tissues was observed. When β-galactoside-binding protein-3 expression in gast ric cancerous tissues was compared with that in normal gastric tissues, there was a significant difference. Conclusion 　A significantly stronger expression of β-galactoside-binding protein-3 in cancerous tissues was observed. β-galactoside-binding protein-3 might be a useful tumor marker for gast ric carcinomas with respect s to tumor metastasis, proliferation, cancer progression, and tumor cell adhesion.