Objective:To investigate the expression of CD90 and its clinical significance in gastric cancer tissues. Methods: The expressions of CD90 in gastric cancer tissues, adjacent tissues and chronic gastritis tissues were detected by immunohistochemical staining to analyze their relationship with clinical pathological features and prognosis in gastric cancer. Result: The positive expression rate of CD90 was 66.7%(64/96)in gastric cancer tissues, 15.6%(15/96)in adjacent normal tissues, and 15.0% (3/20) in chronic gastritis tissues, with a statistically significant difference (P < 0.01). The expression of CD90 in gastric cancer was associated with the TNM stage (P=0.014, P T=0.02,PN=0.017 and PM =0.045). Multivariate survival analysis indicated that patients with high expression of CD90 had poorer 5-year overall survival (P < 0.05). Conclusion: CD90 is associated with the invasion and metastasis of gastric cancer, and may be helpful in providing a novel molecular therapeutictarget and evaluating prognosis of gastric cancer.