Objective:To investigate the expression of cyclooxygenase2 (COX2),urokinase plasminogen activator(uPA),and thrombospondin1 (TSP1) in gastric carcinoma and the surrounding lymph nodes,so as to discuss their roles in the invasion and metastasis of gastric carcinoma.Methods:The expression of COX2,uPA,and TSP1 in the samples was examined by tissue microarray and SP immunohistochemistry staining.Results:The positive rates of COX2,uPA,and TSP1 in gastric carcinoma were 67.7%,78.1%,and 78.6%,respectively,which were significantly higher than those in the surrounding lymph nodes(40.0%,6.7%, and 40.0%,respectively,P＜0.05).The expression of COX2 was significantly correlated with the depth of invasion (P＜0.05）.The expression of uPA was significantly correlated with lymph node metastasis and depth of invasion (P＜0.05).The expression of TSP1 was neither correlated with lymph node metastasis nor depth of invasion (P>0.05).COX2,uPA,and TSP1 expression was not significantly different between metastatic lymph nodes and corresponding gastric carcinoma.COX2 expression was positively correlated with uPA,and TSP1 expression.TSP1 expression was not correlated with uPA expression.Conclusion:COX2,uPA,and TSP1 are highly expressed in the gastric carcinoma.COX2 expression is correlated with depth of invasion.UPA expression is significantly related with depth of invasion and lymph node metastasis.