Objective: To study the expression of CD44 correlation and the ability of metastasis of tumor cells in gastric carcinoma, and to find the correlation of the quantitative of CD44V6mRNA and the histology expression of CD44v6 in tumors with the clinic-pathologic features, and to make the quantitative expression of CD44v6mRNA. Methods: Twenty patients with gastric carcinoma, 4patients with gastritis, and 10 apparently healthy controls were recruited. Blood samples were obtained before surgery. 10 days after surgery, the blood samples were obtained again. Serum CD44v6mRNA in all cases was measured by real-time quantitative PCR. Results:Serum CD44V6mRNA was detectable in 20 of 20( 100％ ) gastric carcinoma cases, The expression level ranged from 4.9 × 102 copies/μg RNA to 3.2 × 10s copies/μg RNA, the average levels of peripheral blood was 3.9 × 104 copies/μg RNA, The expression level of peripheral blood of gastric cancer after curative operation ranged from 5.5 × 100 copies/μg RNA to 7.6 × 103 copies/μg RNA. After curative operation the expression level was decreased markedly. Conclusion: Serum CD44v6mRNA is expressed in the peripheral blood of gastric carcinoma patients. The expression level of CD44V6mRNA is obviously decreased after curative operation. An elevated level of CD44v6mRNA may serve as an indicator of lymph node metastasis (especially early metastasis) and bad prognosis in patients with gastric carcinoma.