Objective: To study the expression and significance of KAI1/CD82, p27 proteins in gastric carcinoma. Methods: The expressions of KAI1/CD82, p27 proteins were detected by immunohistchemistry S-P method in 58 cases of gastric carcinoma tissues and 23 normal gastric tissues. Results: The positive rates of KAI1/CD82 and p27 proteins in gastric carcinoma tissues were 29.3% and 34.4%, but 90% and 85% respectively in normal gastric tissue. And there is a significant difference between the two groups. The expression level of KAI1/CD82 and p27 proteins was significantly related to tumor invasive depth, grade of tumor differentiation, the clinical stage and lymph node metastasis, And has nothing to do with age or gender. There was a positive correlation between the expression of KAI1/CD82 and P27 in gastric cancer tissues. Conclusion: The expression of KAI1/CD82 and p27 protein may be involved in the initiation and development in gastric carcinoma, and the combined detection of KAI1/CD82 and p27 proteins may be significant in predicting the invision and metastasis of gastric carcinoma.