ObjectiveTo investigate the expression and clinical significance of tumor infiltrating dendritic cells(TIDCs) within gastric tumor tissues. MethodsImmunohistochemistry(IHC),insitu hybridization(ISH) and flow cytometry were applied to detect the expression of S100, CD83 mRNA and CD83 on DCs in 45 gastric adenocarcinoma tissues. The corelationship of the S100 and CD83 expression with clinical pathologicalfeatures was analyzed. ResultsIHC showed that S100 expression was unevenly distributed within42 cancer tissue and CD83 was only expressed in tumoradjacent tissue and normal tissue. ISH showed that CD83 mRNA was limitedly expressed within 7 samples. S100 expression had no significant correlationwith clinical pathological features, while CD83 reversely correlated with TNM stages. Detected by flow cytometry, CD83 was expressed in low level in all 45 gastric cancer tissues and negative correlations were found with lymph node metastasis and TNM stages of gastric cancer(r=-0.879,P<0.01; r=-0.782, P<0.05). ConclusionsTIDCs in gastric cancer tissue mainly appear in an immature state. The expression of S100 suggests the amount of TIDCS, while CD83 suggests their function. CD83 expression correlated with lymph node metastasis and TNM stages of gastric cancer, and could be used as a marker in further research.