Abstract: Objective To study two topic genes in gastric carcinoma-CD44 and p53,and the relationship between they and carcinogensis,invasion and metastasis of gastric carcinoma. Methods Expression of CD44 and p53 genes was immunohistochemically detected in 78 gastric carcinomas and 46 benign gastric mucosa lesions adjacent to carcinoma by monoclonal antibodies of 2F10 (anti-CD44V6) and DO-1 (anti-p53).The relationship between CD44 and p53 gene expression and each of the clinicopatholgic characteristics was analysed and statistically tested. Results Expression of CD44V6 was observed in 30 gastric carcinornas (38.5%),not in benign mucosa lesions adjacent to carcinoma.The incidence of CD44V6 positivity was higher in carcinomas with serosa invasion,lymph node or distance metastasis than those without (P<0.05).The intestinal type carcinoma was more frequently CD44V6 positive than the diffuse type carcinoma (P<0.05).However,expression of CD44V6 was significantly associated with node metastasis in the diffuse type (P<0.05)，not in the intestinal type carinoma.CD44V6 positivity had no relation to tumor size,age and sex of patients.p53 protein accumulation was detected in 28 gastric carcinomas (35.9%) and 5 benign lesions adjacent to carcinoma (10.9%),prositivity of p53 protein was not correlated with each of the clincopathologic characteristics. Conclusion These results suggested that CD44V6 may be involved in invasion and metastasis of gastric carcinoma.It's expression indicated that gastric carcinoma had stronger invasion and metastasis potential.p53 gene alteration occurred in early stage of gastric carcinoma development, and may be associated with gastric epithelium carcinogenesis.