Objective:To evaluate the expression of CD44s and CD44v6 in colorectal carcinoma and its clinical significance. Methods:The expressions of CD44s and CD44v6 in tumor tissue were detected by immunohistochemically in 57 patients with colorectal carcinoma. Results:The positive rates of CD44s and CD44v6 were 66.7% and 63.2%,respectively. There was significant correlation between CD44s immunoreactivity and Duke＇s stage,the grade of tumor (P < 0.05,Spearman correlation test). Significant correlation between CD44v6 immunoreactivity and the grade of tumor,Duke’s stage,lymph node metastasis was also noticed (P < 0.05,Spearman correlation test). The 5-year survival rates were 78.95% and 55.26% in CD44s negative cases and CD44s positive ones,respectively. The difference between the two groups was not significant (P > 0.05,Log-rank test). As CD44v6,the 5-year survival rates were 80.95% and 52.78% in CD44v6 negative cases and CD44v6 positive ones,respectively.The difference between the two groups was significant (P < 0.05,Log-rank test). In multivariate analysis using the Cox regression model,CD44v6 expression emerged as an independent prognostic indicator. Conclusion:CD44s and CD44v6 might play important roles in metastasis of colorectal carcinoma,and the expression of CD44v6 might be a new useful independent prognostic marker of colorectal carcinoma.