Objective To investigate the expression of cerb B2 and CathepsinD in gastric carcinoma and its correlation with the biological behavior of gastric carcinoma (GC). MethodsThe expression was studied by immunohistochemical technique. The expression of cerb B2 and CathepsinD were analyzed with their relation to histologic types, depth of invasion, growth pattern, lymph node metastasis and prognosis of gastric carcinoma. ResultsThirtynine of the 102 gastric carcinoma specimens (38.24%) were positive for cerb B2 and correlated with depth of invasion (P<0.05) and lymph node metastasis (P<0.05); eightythree of the 102 gastric carcinoma specimens (81.37%) were positive for CathepsinD and correlated with depth of invasion (P<0.05), growth pattern (P<0.05), lymph node metastasis (P<0.05) and blood vessels cancer embolus (P<0.05). Prognosis of patients with gastric carcinoma with positive expression of cerb B2 or CathepsinD was poor. The 5year survival rate was significantly lower in gastric carcinoma patients with positive expression of cerb B2 or CathepsinD. Conclusion cerb B2 and CathepsinD are highly related to growth, invasion, metastasis and prognosis of gastric carcinoma.