Abstract: Paraffin-embedded materials from 114 patients with primary gastric cancer were examined for the expression of Estrogen Receptor (ER), ER positive cases were characterized grossly as Borrmann Ⅳ、TNM Ⅲ、Ⅳ and microscopically as diffuse type with scirrhows growth pattern. A significant positive correlation was found between ER status and lymph node status. The five-year surrival rate of patients with positive ER was Lower than thoses with negative ones. These results indicate that the sex hormonal factors are involved in gastric cancer. and ER detected by ABC method may be used as biomarkers for tumor differentiation and have Prognostic values in gastric cancer.