Objective:To investigate the expression of c-Jun and MMP-9 in gastric cancer tissues,para-cancerous tissues and metastastic lymph nodes,and to explore its role and significance for the clinicopathology and prognosis.Methods:Immunohistochemistry was employed to detect the expression of c-Jun and MMP-9 in tissue microarrays containing gastric normal mucosa(n=32),para-cancerous tissues(n=54),metastastic lymph nodes(n=41),and gastric cancer tissues(n=189).Results:The positive rates for c-Jun and MMP-9 expression in gastric cancer were 73.0%and 78.3%,respectively.The positive rates of c-Jun protein was significantly associated with the degree of differentiation(P<0.05),but was not associated with the depth of invasion,lymph node metastasis,Lauren type,sex,age or size of tumor(P>0.05).The positive rates of MMP-9 was significantly associated with the depth of invasion,lymph node metastasis,Lauren type and degree of differentiation(P<0.05),but was not associated with sex,age or size of tumor(P>0.05).The positive rates of MMP-9 expression in the 41 gastnc cancer tissue samples and 41 metastastic lymph node tissue samples were significantly different(P<0.05).In metastastic lymph nodes,the positive rate of MMP-9 expression was higher.Kaplan-Meier survival analysis showed that the survival rate of patients with negative c-Jun and MMP-9 expression was higher than that of patients with positive c-Jun and MMP-9 expression(P<0.05).COX regression analysis showed that c-Jun and MMP-9 expressioh was not independent prognostic factor for gastric cancer. Conclusion:The expression of c-Jun is positively associated with the degree of differentiation.The increased c-Jun expression maybe an early indicator of gastric Cancer. The high expression of MMP-9 may involve the Occurrence,development,invasion,and metastasis of gastric cancer. C-Jun and MMP-9 are useful markers for predicting the outcome of gastric cancer,but they are not independent prognostic factors.