Abstract: To study the effect of Her2/neu and Syndecan1 in gastric carcinoma. Methods: The expressions of Her2/neu and Syndecan1 were measured by using immunohistochemistry method in 112 patients with gastric cancer and 40 healthy controls. Results： ① Her2/neu was expressed in 20.5 % of the gastric cancer tissue and 5.0% of the healthy gastric mucosa (χ2＝5.17， P ＜ 0.05)， and Syndecan1 was expressed in 46.4% of the gastric cancer tissue and 100% of the healthy mucosa (χ2＝20.80，　P＜ 0.01)； ② the expression of Her2/neu was significantly correlated with the differentiation, lymph node metastasis and clinical stage (P＜0.05) and depth of invasion (P＜0.01); ③ the expression of Syndecan1 was significantly correlated with the differentiation and the lymph node metastasis (P＜ 0.01). Conclusion： ① The expression of Her2/neu is significantly correlated with the clinicopathological factors (P＜0.05) which suggests that Her2/neu is a risk factor for gastric cancer;　② the expression of Syndecan1 is significantly correlated with the differentiation and the lymph node metastasis, which suggests that Syndecan1 is a protective factor for gastric cancer;　 ③　the expression of Her2/neu in gastric cancer tissue is significantly correlated with that of Syndecan1.

Key words: Gastric neoplasms, Her2/neu, Syndecan1, Immunohistochemistry, Clinical grade, Tumor metastasis, Prognosis